#include <stdio.h>
#include <stdint.h>
#include <math.h>

int factor(int x){
    if (x == 0) return 1;
    else return x * factor(x - 1);
}

int zero_count(int x){
    int32_t cnt = 0;
    while (x == 0){
        if (x % 10 == 0){
            cnt++;
            x /= 10;
        }else break;
    }
    return cnt;
}

int main(){
    int a;
    FILE* input;
    input = fopen("fact.in", "r");
    fscanf(input, "%d", &a);
    FILE* output;
    output = fopen("fact.out", "w");

    for (int i = 0; i < 10 * a; ++i){
        if (zero_count(factor(i)) == a){
            fprintf(output, "%d", i);
            break;
        }else continue;
    }

    fclose(input);
    fclose(output);
    return 0;
}