#include<bits/stdc++.h>
#define rep(i,a,b) for(int i=a;i<b;i++)
#define rrep(i,a,b) for(int i=a;i>=b;i--)
#define fore(i,a) for(auto &i:a)
#pragma GCC optimize ("-O3")
using namespace std; void _main(); int main() { cin.tie(0); ios::sync_with_stdio(false); _main(); }
//---------------------------------------------------------------------------------------------------
#include <boost/multiprecision/cpp_int.hpp>
typedef boost::multiprecision::cpp_int bigint;
/*---------------------------------------------------------------------------------------------------
????????????????????????????????? ??§?????§  
??????????????? ??§?????§ ???????´<_??? ?????? Welcome to My Coding Space!
???????????? ??? ?´_???`??????/??? ???i     
?????????????????????????????? ???  |???|     
????????? /?????? /??£??£??£??£/??????|  
??? ???_(__??????/???    ???/ .| .|????????????  
??? ????????????/????????????/??????u??????  
---------------------------------------------------------------------------------------------------*/
 




int N;
bigint A, B;
//---------------------------------------------------------------------------------------------------
void _main() {
    cin >> N;
    rep(i, 0, N) {
        cin >> A >> B;

        bigint ans = A + B;
        string str = ans.str();

        if (80 < str.size()) printf("overflow\n");
        else printf("%s\n", str.c_str());
    }
}