#include <iostream>
#include <string>
using namespace std;


string F(string a,string b)
{
    int i=0,CF=0,JG=0,loop=0;
    string c;
    char *pa,*pb;
    if (a.length()>b.length())
    {
        b.insert(b.begin(),a.length()-b.length(),0x30);
    }
    else
    {
        a.insert(a.begin(),b.length()-a.length(),0x30);
    }
    pb=(char*)a.c_str()+a.length()-1;
    pa=(char*)b.c_str()+b.length()-1;
    for (i=0;i<a.length() || i<b.length();i++)
    {
        JG=(*pa--)+(*pb--)+CF-0x60;
        CF=JG/10;
        JG%=10;
        c.insert(c.begin(),1,JG+0x30);
    }
    if (CF)
    {
        if (i<a.length())
        {
            JG=*pa+CF-0x30;
            CF=JG/10;
            JG%=10;
            c.insert(c.begin(),1,JG+0x30);
        }
        else
        {
            c.insert(c.begin(),1,CF+0x30);
        }
    }
    return c;
}
int main()
{
    int N,i;
    cin>>N;
    string a,b,sum;
    for (i=1;i<=N;i++)
    {
        cin>>a>>b;
        sum=F(a,b);
        if(sum.length()>80)
            cout<<"overflow"<<endl;
        else
            cout<<sum<<endl;
    }
    return 0;
}