#include <iostream>
#include <cstring>
#include <algorithm>

using namespace std;

typedef long long LL;

LL n, m, k;

bool check(LL mid)
{
    LL res = 0;
    for (int i = 1; i <= n; i ++)
        res += min(m, mid / i);

    return res >= k;
}

int main()
{
    cin >> n >> m >> k;

    LL l = 1, r = n * m;
    while (l < r)
    {
        LL mid = l + r >> 1;
        if (check(mid)) r = mid;    //判断是不是满足性质；
        else l = mid + 1;
    }

    cout << r << endl;

    return 0;
}