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