#include <iostream>
#include <cmath>

bool IsSpaciousEnough(int width, int height, int diplomas_amount, int64_t side) {
    return diplomas_amount <= (side / width) * (side / height);
}

int64_t BinarySearch(int width, int height, int diplomas_amount) {
    int64_t left = 0;
    int64_t right = static_cast<int64_t>(std::ceil(std::sqrt(diplomas_amount))) * std::max(width, height);
    while (right - left > 1) {
        auto middle = (left + right) / 2;
        if (IsSpaciousEnough(width, height, diplomas_amount, middle)) {
            right = middle;
        } else {
            left = middle;
        }
    }
    return right;
}

int main() {
    int width;
    int height;
    int diplomas_amount;
    std::cin >> width >> height >> diplomas_amount;
    std::cout << BinarySearch(width, height, diplomas_amount);
    return 0;
}