#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b, r;
  cin >> a >> b >> r;
  int x = (a / (2 * r)) * (b / (2 * r));
  if (2 * r <= min(a, b))
    cout << "First";
  else
    cout << "Second";
  return 0;
}
