def fact(n):
    result = 1
    for i in range(1, n + 1):
        result *= i
    return result


def zero_in_start(n):
    print(n)
    result = 0
    if n == 0:
        return 1
    while n > 0:
        yekan = n % 10
        if(yekan != 0):
            break
        result += 1
        n = int(n / 10)
    return result

n = int(input("Enter positive number:"))
print(f"{n}! = {fact(n)}\nTrailing zeros: {zero_in_start(fact(n))}")

#include <stdbool.h>
#include <stdio.h>
#define MAX_FIB 1000000

long fib(int n) {
    static long cache[MAX_FIB];
    static bool isRan = false;
    if (!isRan) {
        isRan = true;
        for (int i = 0; i < MAX_FIB; i++) {
            if (i == 0 || i == 1) {
                cache[i] = i;
            } else {
                cache[i] = -1;
            }
        }
    }
    if (cache[n] != -1) {
        return cache[n];
    }
    cache[n] = fib(n - 1) + fib(n - 2);
    return cache[n];
}

int main(void) {
    for (int i = 0; i < 90; i++) {
        printf("fib(%d) = %ld\n", i, fib(i));
    }
    return 0;
}