#include <bits/stdc++.h>
int main(void) {
  int a, b, c, max;
  printf("aの個数:");
  scanf("%d", &a);
  printf("bの個数:");
  scanf("%d", &b);
  printf("cの個数:");
  scanf("%d", &c);
  if (a > b && a > c) {
    max = a;
    if (max == b + c)
      printf("yes\n");
    else
      printf("no\n");
  }
  if (b > a && b > c) {
    max = b;
    if (max == a + c)
      printf("yes\n");
    else
      printf("no\n");
  }
  if (c > a && c > b) {
    max = c;
    if (max == a + b)
      printf("yes\n");
    else
      printf("no\n");
  }
  return 0;
}
