#include <iostream>
#include <algorithm>
#include <vector>

void solve() {
    std::vector<int> xs(4);
    for (auto& x : xs) std::cin >> x;

    std::sort(xs.begin(), xs.end());
    xs.erase(std::unique(xs.begin(), xs.end()), xs.end());

    bool ans = (xs.size() == 4 && xs.back() - xs.front() == 3);
    std::cout << (ans ? "Yes" : "No") << std::endl;
}

int main() {
    std::cin.tie(nullptr);
    std::cout.tie(nullptr);
    std::ios::sync_with_stdio(false);

    solve();

    return 0;
}