题解

#include<iostream>
#include<string>
using namespace std;
int main(){
    string x;
    cin>>x;
    int sum=0;
    for(int i=0;i<x.size();i++){
        if(int(x[i]-'0')%2==0){
            sum+=int(x[i]-'0');
        }
    }
    cout<<sum<<x;
    return 0;
}