#include <set>
#include <map>
#include <list>
#include <queue>
#include <stack>
#include <cmath>
#include <ctype.h>
#include <ctime>
#include <cstdio>
#include <vector>
#include <string>
#include <bitset>
#include <cctype>
#include <cstdlib>
#include <cstring>
#include <utility>
#include <numeric>
#include <complex>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <cassert>
#include <iostream>
#include <iterator>
#include <algorithm>

using namespace std;

#define REP(i, x, n) for(int i = x; i < n; i++)
#define rep(i, n) REP(i, 0, n)
#define lengthof(x) (sizeof(x) / sizeof(*(x)))
#define FILL(ptr, value) FILL_((ptr), sizeof(ptr)/sizeof(value), (value))
template <typename T>
void FILL_(void * ptr, size_t size, T value){
  std::fill((T*)ptr, (T*)ptr+size, value);
}
//4方向ベクトル→↑←↓
int dx[] ={1,0,-1,0};
int dy[] ={0,-1,0,1};
int n;
int main()
{
  scanf("%d",&n);
  for(int i = 0;i < n;i++){
    string str1;
    string str2;
    string str3;
    cin>>str1>>str2;
    int size =max(str1.size(),str2.size());
    while(str1.size()<size)
      str1 ='0'+str1;
    while(str2.size()<size)
      str2 ='0'+str2;
    int c = 0;//桁上り
    for(int j = size-1;j >=0;j--){
      char ch = ((str1[j]-'0')+(str2[j]-'0')+c)%10+'0';
      c =((str1[j]-'0')+(str2[j]-'0')+c)/10;
      str3 =ch+str3;
  }
    if(c){
      char cs =c+'0';
      str3 = cs+str3;
    }
    while(str3.size()>1 &&str3[0] =='0')
      str3.erase(str3.begin());
    if(str3.size() >80)
      cout <<"overflow"<<endl;
    else
      cout <<str3<<endl;
  }
  return 0;
}