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