#include <cstdio>

#include <cmath>

int p[] = {, , , , , , , , , , , , , , };

long long n, result =  << ;

int maxDivisors = ;

void dfs(long long res, int divisors, int np, int ti) {

    if (np >  || res > n) return;

    if (divisors > maxDivisors || (divisors == maxDivisors && res < result)) {

        maxDivisors = divisors;

        result = res;

    }

    int t = p[np];

    int i = ;

    long long val;

    while ((val = res * std::pow(t, i)) < n && i <= ti) {

        dfs(val, divisors * (i + ), np + , i);

        ++i;

    }

}

int main() {

    scanf("%lld", &n);

    dfs(, , , );

    printf("%lld\n", result);

    return ;

}