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

#define int long long
#define F first
#define S second
#define MP make_pair
#define endl "\n"

const double PI = acos(-1.0);
const int mod = 1e9 + 7;
const int inf = 1e9 + 5;
const int linf = 1e18;

void solve() {
    int n; cin >> n;
    vector<int> arr;
    while (n) {
        arr.push_back(n % 10);
        n /= 10;
    }
    arr[0] + arr[2] == arr[1] ? cout << "Yes" : cout << "No";
}

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);

    // File I/O
#ifdef LOCAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif

    solve();

    return 0;
}