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

string sum( string sa, string sb ){
    string ret = "0";
    int len = max( sa.size(), sb.size() );
    reverse( sa.begin(), sa.end() );
    reverse( sb.begin(), sb.end() );
    while( sa.size()<len )  sa += '0';
    while( sb.size()<len )  sb += '0';
    for( int i=0; i<len; i++ ){
        ret[i] += sa[i]-'0' + sb[i]-'0';
        if( ret[i] > '9' ){
            ret += '1';
            ret[i] -= 10;
        }else if( i!=len-1 ){
            ret += '0';
        }
    }
    reverse( ret.begin(), ret.end() );
    if( ret.size() > 80 ){
        ret = "overflow";
    }
    return ret;
}

int main(){
    int n;
    cin >> n;
    while(n--){
        string a, b;
        cin >> a >> b;
        cout << sum(a, b) << endl;
    }
    return 0;
}