#include <bits/stdc++.h>
using namespace std;
int main(int argc, char *argv[]) {
  long long tmp1, tmp2, tmp3, a[5];
  while (~scanf("%lld%lld%lld", &a[0], &a[1], &a[2])) {
    sort(a, a + 3);
    tmp1 = 0x3f3f3f3f3f3f3f3f;
    tmp2 = 0x3f3f3f3f3f3f3f3f;
    tmp3 = 0x3f3f3f3f3f3f3f3f;
    if ((a[1] - a[0]) % 2 == 0) {
      tmp1 = a[1];
    }
    if ((a[2] - a[0]) % 2 == 0) {
      tmp2 = a[2];
    }
    if ((a[2] - a[1]) % 2 == 0) {
      tmp3 = a[2];
    }
    printf("%lld\n", min(min(tmp1, tmp2), tmp3));
  }
  return 0;
}
