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