#include <bits/stdc++.h>
using namespace std;

#define rep(i, a, b) for (int i = a; i < b; i++)
using ll = long long;

int main(){
	string ns;
	cin >> ns;
	vector<int> a(3);
	rep(i, 0, 3){
		a[i] = ns[i] - '0';
	}
	if(a[0] + a[2] == a[1]) cout << "Yes" << endl;
	else cout << "No" << endl;
}