#include <cstdio>

long long cit() {
    long long ans = 0;
    char c = getchar();
    bool neg = false;
    while (c < '0' || c > '9') {
        if (c == '-') {
            c = getchar();
            neg = true;
            break;
        }
        c = getchar();
    }
    while (c >= '0' && c <= '9') {
        ans = (ans << 3) + (ans << 1) + (c - '0');
        c = getchar();
    }
    return (neg) ? -ans : ans;
}

void afis(long long n) {
    int l = 0;
    char c[20];
    if (n == 0) {
        putchar('0');
    }
    if (n < 0) {
        putchar('-');
        n = -n;
    }
    while (n > 0) {
        c[l++] = n % 10 + '0';
        n /= 10;
    }
    for (int i = l - 1; i >= 0; i--) {
        putchar(c[i]);
    }
    putchar('\n');
}


int main() {
    freopen("fact.in", "r", stdin);
    freopen("fact.out", "w", stdout);

    int p = cit();
    if (p == 0) {
        afis(1);
        return 0;
    }
    int aux = 5 * ((4 * p) / 5);
    while (p > 0) {
        aux += 5;
        int n = 0, r = aux;
        while (r % 5 == 0) {
            n++;
            r /= 5;
        }
        p -= n;
    }

    afis((p == 0) ? aux : -1);

    return 0;
}