#include <fstream>

using namespace std;

int n;
void read();
void solve();
void write();
int main(){
    read();
    solve();
    return 0;
}

void read(){
    freopen("fact.in","r",stdin);
    scanf("%d",&n);
}

void solve(){
    int nr=0;
    int k=1;
    if (n==0){
        printf("1");
    }
    else {
        while (nr<n){
            int i=k*5;
            while (i%5==0){
                i/=5;
                nr++;
            }
            k++;
        }
        k--;
        if (nr==n){
            printf("%d",k*5);
        }
        else {
            printf("-1");
        }
    }
}