#include <fstream>
#include <cstdio>
#include <bitset>

using namespace std;

const int MAX_N = 1000005;
const int MOD = 666013;

ofstream fout ("supersuma.out");

int T, K, P[MAX_N];
bitset <MAX_N> viz;

void ciur() {
    for(int i = 2; i < MAX_N; ++i) {
        if(viz[i] == 0) {
            P[++K] = i;

            for(int j = i+i; j < MAX_N; j += i) {
                viz[j] = 1;
            }
        }
    }
}

inline int pow(int x, int p) {
    int rez = 1;

    for(; p; p >>= 1) {
        if(p & 1) {
            rez *= x;
            rez %= MOD;
        }

        x *= x;
        x %= MOD;
    }

    return rez;
}

long long solve(int N) {

    long long nd = 1, sd = 1;

    for(int i = 1; i <= K && 1LL * P[i] * P[i] <= N; ++i) {
        if(N % P[i]) continue;
        int p = 0;

        while(N % P[i] == 0) {
            N /= P[i];
            ++p;
        }

//        int p1 = (pow(P[i], p+1) - 1);
//        int p2 = pow(P[i]-1, MOD-2);
//
//        sd = (((sd * p1)) * p2)%MOD;
            sd *= (pow(P[i], p + 1) - 1) / (P[i] - 1);
    }

    if(N > 1) {
        sd *= N + 1;
    }

    return sd;
}

int main() {
    long long n;
    freopen("supersuma.in", "r", stdin);
    scanf("%lld", &n);
  //  printf("%d\n", n);
    ciur();
    int i;
    i = 1;
    long long suma = 0;
    while(suma < n)  {
        suma += solve(i);
 //       printf("%d ", solve(i));
        i++;
    }

    fout<<i-1;
    return 0;
    return 0;
}