diff --git a/Hat_Check_Problem.c b/Hat_Check_Problem.c
new file mode 100644
index 0000000..ccb2ddb
--- /dev/null
+++ b/Hat_Check_Problem.c
@@ -0,0 +1,22 @@
+#include <stdio.h>
+ 
+// Recursive function to count the derangements of an n–element set
+int derangements(int n)
+{
+    // base case
+    if (n == 1 || n == 2) {
+        return n - 1;
+    }
+ 
+    // recur using the recurrence relation
+    return (n - 1) * (derangements(n - 1) + derangements(n - 2));
+}
+ 
+int main(void)
+{
+    int n = 4;
+    printf("The total number of derangements of a %d–element set is %d",
+        n, derangements(n));
+ 
+    return 0;
+}