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