#include<iostream>
#include<string>

using namespace std;

int main(void)
{
    string s;
    cin>>s;
    
    int ans=0;
    
    for(int i=0;i<s.size();i++)
    {
        if('1'<=s[i]&&s[i]<='9')
        {
            ans+=s[i]-'1'+1;
        }
    }
    cout<<ans<<endl;
}