#include <cstdio>
#define MIN(A,B) A <= B ? A : B
using namespace std;

FILE *f = freopen("fact.in", "r", stdin);
FILE *g = freopen("fact.out", "w", stdout);

int ret(int p) {
    if(p == 0) return 1;
    int nr2 = 0, nr5 = 0;
    int n = 1, k = 1;
    bool ok = false;
    while(!ok) {
        n = k;
        while(n % 2 == 0) {
            nr2 ++; n/= 2;

        }
        while(n % 5 == 0) {
            nr5 ++; n/= 5;
        }
        if(MIN(nr2, nr5) == p)
            return k;
        k ++;
    }
}
int main() {
    int p;
    scanf("%d", &p);
    printf("%d ", ret(p));
    return 0;
}