#include <bits/stdc++.h>

#include <atcoder/all>
using namespace std;
using i32 = int;
using u32 = unsigned int;
using i64 = long long;
using u64 = unsigned long long;
#define FAST_IO                \
  ios::sync_with_stdio(false); \
  cin.tie(0);
const i64 INF = 1001001001001001001;
using Modint = atcoder::static_modint<998244353>;

int main() {
  FAST_IO

  string s;
  cin >> s;
  int a = s[0] - '0';
  int b = s[1] - '0';
  int c = s[2] - '0';
  if (a + c == b) {
    cout << "Yes" << endl;
  } else {
    cout << "No" << endl;
  }
}