#include<bits/stdc++.h>
using namespace std;
char strn[1000],str1[101],str2[101];
void add(int one,int two)
{
    int n,carry=0;
    for(int i=0;one-i>=0||two-i>=0||carry==1;i++){
        if(one-i>=0&&two-i>=0)n=(str1[one-i]-'0')+(str2[two-i]-'0');
        else if(one-i>=0)n=(str1[one-i]-'0');
        else if(two-i>=0)n=(str2[two-i]-'0');
        else n=0;
        if(n+carry>9){
            strn[i]=n+'0'+carry-10;
            carry=1;
        }
        else {
            strn[i]=n+'0'+carry;
            carry=0;
        }
    }
}
int main()
{
    int n,firs,seco,co;
    cin>>n;
    for(int i=0;i<n;i++){
        cin>>str1>>str2;
        firs=strlen(str1);
        seco=strlen(str2);
        if(firs>80||seco>80)cout<<"overflow"<<endl;
        else {
            add(firs,seco);
            co=strlen(strn);
            if(co>80)cout<<"overflow"<<endl;
            else {
                for(int i=co-1;i>0;i--)printf("%c",strn[i]);
                cout<<endl;
            }
        }

    }
}