#include <iostream>
#include <string>
using namespace std;

int main(){
    int N;
    cin >> N;
    string sn = to_string(N);

    int a = (int)(sn[0] - '0');
    int b = (int)(sn[1] - '0');
    int c = (int)(sn[2] - '0');
    cout << (a + c == b ? "Yes" : "No") << endl;
}