#include <bits/stdc++.h>
using namespace std;
# pragma GCC target("avx2")
# pragma GCC optimize("O3")
# pragma GCC optimize("unroll-loops")

using ll=long long;
using current=pair<int, pair<int, int>>;
int nibutan(int n, vector<int> A, int key){
    int ok=n;
    int ng=-1;
    while(ok-ng>1){
        int mid=(ok+ng)/2;
        if(A[mid]>key){
            ok=mid;
        }else{
            ng=mid;
        }
    }
    return ok;
}
void update(int i, int n, int x, vector<int> &data){
    i+=n-1;    
    data[i]= x;
        while(i>1){
            i/=2;
            data[i]=max(data[i*2], data[i*2+1]);
        }
    }
int get(int n, int l, int r, vector<int> &data){
        int res=0;
        l+=n-1;
        r+=n-1;
        while(r>l){
            if(l&1){
                res=max(data[l], res);
                l++;
            }
            l>>=1;
            if(r&1){
                r--;
                res=max(res, data[r]);
            }
            r>>=1;
        }
        return res;
}
int main(){
    string S;
    cin >> S;
    if((S[0]-'0')+(S[2]-'0')==(S[1]-'0')){
        cout << "Yes";
    }else{
        cout << "No";
    }
}