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