diff --git a/day11/input.txt b/day11/input.txt
new file mode 100644
index 0000000..1eedc56
--- /dev/null
+++ b/day11/input.txt
@@ -0,0 +1,77 @@
+8
+6
+99
+63
+76
+93
+54
+73
+0 1 11
+2
+7
+1
+4
+91
+60
+97
+54
+0 0 1
+17
+3
+2
+1
+65
+0 0 7
+7
+6
+5
+2
+84
+55
+0 0 3
+11
+2
+6
+5
+86
+63
+79
+54
+83
+0 1 0
+19
+7
+0
+7
+96
+67
+56
+95
+64
+69
+96
+0 0 4
+5
+4
+0
+8
+66
+94
+70
+93
+72
+67
+88
+51
+0 1 5
+13
+4
+5
+3
+59
+59
+74
+0 0 8
+3
+1
+3
diff --git a/day11/monkeys b/day11/monkeys
new file mode 100755
index 0000000..a89c2b3
Binary files /dev/null and b/day11/monkeys differ
diff --git a/day11/monkeys.c b/day11/monkeys.c
new file mode 100644
index 0000000..79d88e4
--- /dev/null
+++ b/day11/monkeys.c
@@ -0,0 +1,144 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define BUFFER_SIZE 64
+#define MONKEY_MAX_STASH 100
+#define substitute(w, o) (o == 0 ? w : o)
+
+enum stage {
+    INIT,
+    ITEM_COUNT,
+    ITEMS,
+    OPERATION,
+    TEST,
+    THROW_TRUE,
+    THROW_FALSE
+};
+
+typedef struct monkey {
+    unsigned long stash[MONKEY_MAX_STASH];
+    unsigned long stash_size;
+    int test;
+    int throw_true;
+    int throw_false;
+    int operation[3];
+    unsigned long throw_count;
+} MONKEY;
+
+unsigned long operate(unsigned long, int*);
+
+int main() {
+    char buf[BUFFER_SIZE], *p, c;
+    memset(buf, 0, BUFFER_SIZE);
+    p = buf;
+
+    enum stage currentStage = INIT;
+
+    MONKEY *monkeys, *currentMonkey;
+    int monkeyCount, itemRemaining;
+
+    while ((c = getchar()) != EOF) {
+        *p++ = c;
+        if (c == '\n') {
+            switch (currentStage) {
+                case INIT:
+                    sscanf(buf, "%i", &monkeyCount);
+                    monkeys = (MONKEY*)malloc(monkeyCount*sizeof(MONKEY));
+                    memset(monkeys, 0, monkeyCount*sizeof(MONKEY));
+                    currentMonkey = monkeys;
+                    currentStage = ITEM_COUNT;
+                    break;
+                case ITEM_COUNT:
+                    sscanf(buf, "%i", &itemRemaining);
+                    currentStage = ITEMS;
+                    break;
+                case ITEMS:
+                    sscanf(buf, "%lu", &currentMonkey->stash[currentMonkey->stash_size]);
+                    currentMonkey->stash_size++;
+                    itemRemaining--;
+                    if (itemRemaining == 0) {
+                        currentStage = OPERATION;
+                    }
+                    break;
+                case OPERATION:
+                    sscanf(buf, "%i %i %i", &currentMonkey->operation[0], &currentMonkey->operation[1], &currentMonkey->operation[2]);
+                    currentStage = TEST;
+                    break;
+                case TEST:
+                    sscanf(buf, "%i", &currentMonkey->test);
+                    currentStage = THROW_TRUE;
+                    break;
+                case THROW_TRUE:
+                    sscanf(buf, "%i", &currentMonkey->throw_true);
+                    currentStage = THROW_FALSE;
+                    break;
+                case THROW_FALSE:
+                    sscanf(buf, "%i", &currentMonkey->throw_false);
+                    currentMonkey++;
+                    currentStage = ITEM_COUNT;
+                    break;
+            }
+
+            memset(buf, 0, BUFFER_SIZE);
+            p = buf;
+        }
+    }
+
+    unsigned long simplifier = 1;
+    for (int j = 0; j < monkeyCount; j++) {
+        simplifier *= monkeys[j].test;
+    }
+
+    unsigned long worry, sumItems;
+    // Play 20 rounds with tha monkeys
+    for (int i = 0; i < 10000; i++) {
+        sumItems = 0;
+        // Each monkeys
+        for (int j = 0; j < monkeyCount; j++) {
+            // Each item
+            for (int k = 0; k < monkeys[j].stash_size; k++) {
+                monkeys[j].throw_count++;
+                worry = monkeys[j].stash[k];
+                worry = operate(worry, monkeys[j].operation);
+                // Don't you worry child
+                // worry /= 3;
+                if (worry % monkeys[j].test == 0) {
+                    monkeys[monkeys[j].throw_true].stash[monkeys[monkeys[j].throw_true].stash_size] = worry % simplifier;
+                    monkeys[monkeys[j].throw_true].stash_size++;
+                } else {
+                    monkeys[monkeys[j].throw_false].stash[monkeys[monkeys[j].throw_false].stash_size] = worry % simplifier;
+                    monkeys[monkeys[j].throw_false].stash_size++;
+                }
+            }
+            monkeys[j].stash_size = 0;
+            memset(monkeys[j].stash, 0, MONKEY_MAX_STASH*sizeof(unsigned long));
+        }
+        // Everything was thrown
+    }
+
+    unsigned long max1 = 0, max2 = 0;
+    for (int i = 0; i < monkeyCount; i++) {
+        if (monkeys[i].throw_count > max1) {
+            max2 = max1;
+            max1 = monkeys[i].throw_count;
+        } else if (monkeys[i].throw_count > max2) {
+            max2 = monkeys[i].throw_count;
+        }
+        printf("Monkey %i throw count: %lu\n", i, monkeys[i].throw_count);
+    }
+
+    printf("\nMonkey business: %lu\n", max1 * max2);
+
+    free(monkeys);
+}
+
+unsigned long operate(unsigned long worry, int* operation) {
+    if (operation[1] == 0) {
+        return substitute(worry, operation[0]) + substitute(worry, operation[2]);
+    } else if (operation[1] == 1) {
+        return substitute(worry, operation[0]) * substitute(worry, operation[2]);
+    }
+
+    return -1;
+}