School 2012 1-st tour A

#include <iostream>
#include <cstdio>

using namespace std;

int ans(int n)
{
    int q = 0;

    while (n)
        {
            q += (n % 2 == 0);

            n /= 10;
        }

    return q;
}

int main()
{
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);

    int n;

    cin >> n;

    cout << ans(n);
}