#include<stdio.h>

int main() {
    int num;
    while(scanf("%d", &num) != EOF) {
        double result = 1;

        for (int i = 1; i <= num; i ++) {
            result = result * i;
        }

        printf("%.0f\n", result);
    }
        
    
    return 0;
}

--------------------------------------------------------------------------------------------

#include<stdio.h>

double digui(double result) {
    if (result > 1) {
        return result * digui(result - 1);
    } 
    return result;
}

int main() {
    int num;
    while(scanf("%d", &num) != EOF) {
        printf("%.0f\n", digui(num));
    }
    
    return 0;
}