#include <bits/stdc++.h>

using namespace std;

int main() {
    vector<int> vt(4);
    set<int> st;
    for (int i = 0; i < 4; ++i) {
        cin >> vt[i];
        st.insert(vt[i]);
    }

    sort(vt.begin(), vt.end());
    if (vt[3] - vt[0] == 3 and st.size() == 4) {
        cout << "Yes" << endl;
    } else {
        cout << "No" << endl;
    }
    return 0;
}