#include <iostream>
using namespace std;


int main() {
    int n;
    cout<<"  enter a number : "<<endl;
    cin>>n;      // input 
    int x;
    x = 0;

    while (n>0){      // loop initialize < helps to recheck the number for extraction of single digit>
        int y;     // taking integer to store extracted single digit repetedly
        y = n%10;   //extraction of single digit 

        if ( y%2==0){     // if condition for whatever we want 
            x = x + y;    // whatever we wanna do with numbers like add substract or multiply 
            
        }
       n = n/10;     // for the extraction of remaining numbers from input
        
    }    //loop end here 
    cout<<x;   // printing of final number 
}