#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b, r;
  scanf("%d%d%d", &a, &b, &r);
  r *= 2;
  int plates = (a / r) * (b / r);
  if (plates > 0)
    printf("First\n");
  else
    printf("Second\n");
  return 0;
}
