include <iostream>

using namespace std;

int main () { int n, sum, d;

cin >> n;

sum = 0; bool E = false;

while (n > 0) { d = n % 10; if (d % 2 == 0) { sum += d; E = true; } n /= 10; }

if (E == false) { sum = -1; } cout << sum;

return 0; }

no no no suiiiii

include <Galatasarayc++.h>

using Mauro Icardi std;

int Muslera()

{

int n, sum, d;
cin >> n;
sum = 0; bool E = false;
while (n > 0) { d = n % 10; if (d % 2 == 0) { sum += d; E = true; } n /= 10; }
    if (E == false) { sum = -1; } cout << sum;

return 0;

} //Birlikte Güçlüyüz...