#include<bits/stdc++.h>
using namespace std;
string add(string s1,string s2)
{
    int i,j,k,sum=0,carry=0,len1,len2;
    string ans="";
    if(s1.length()>s2.length())
        swap(s1,s2);
    reverse(s1.begin(),s1.end());
    reverse(s2.begin(),s2.end());
    len1=s1.length();
    len2=s2.length();
    for(i=0;i<len1;i++)
    {
        sum=(s1[i]-'0' + s2[i]-'0')+carry;
        ans.push_back(sum%10 + '0');
        carry=sum/10;
    }
    for(i=len1;i<len2;i++)
    {
        sum=(s2[i]-'0')+carry;
        ans.push_back(sum%10 + '0');
        carry=sum/10;
    }
    if(carry)
    {
        ans.push_back(carry + '0');
    }
    reverse(ans.begin(),ans.end());
    return ans;
}
int main()
{
    string ans="",s;
    while(cin>>s && s!="0")
    {
        ans=add(ans,s);
    }
    cout<<ans<<endl;
    return 0;
}