#include <bits/stdc++.h>
using namespace std;
int a, b, r;
int main() {
  scanf("%d %d %d", &a, &b, &r);
  int tmp1 = a / 2 - r;
  int tmp2 = b / 2 - r;
  if (tmp1 < 0 || tmp2 < 0) {
    printf("Second\n");
    return 0;
  }
  tmp1 = tmp1 / (2 * r);
  tmp2 = tmp2 / (2 * r);
  printf("First\n");
  return 0;
  return 0;
}
