#include <cstdio>
#include <algorithm>
#include <vector>

int main() {
  std::vector<int> a(4);
  for (auto& ai: a) scanf("%d", &ai);
  std::sort(a.begin(), a.end());
  if (std::unique(a.begin(), a.end()) != a.end()) return puts("No"), 0;
  puts((a[3]-a[0] == 3)? "Yes": "No");
}