#include<iostream>
#include<string>

int main(){
  std::string as;
  std::string bs;
  int a[102]={0};
  int b[102]={0};
  int sum[102]={0};
  int a_size,b_size,sum_size,n,i,j,flag=0,overflow=0;
  char num;

  std::cin >> n;

  for(i=0;i<n;i++){
    std::cin >> as >> bs;
    a_size = as.size();
    b_size = bs.size();

    for(j=0;j<102;j++){   //??????????????????(100??????00100)
      if(101-j<=a_size){
        a[101-j] = as[j-a_size] - '0';
      }else{
        a[101-j] = 0;
      }
      if(101-j<=b_size){
        b[101-j] = bs[j-a_size] - '0';
      }else{
        b[101-j] = 0;
      }
    }

    for(j=0;j<102;j++){       //sum????¨????
      sum[j] = a[j] + b[j];
      if(flag){               //??°?????????
        sum[j] += 1;
        flag = 0;
      }
      if(j>=80&&sum[j]!=0){   //???????????????????????????
        overflow = 1;
        break;
      }
      if(sum[j] > 9){         //??°???????????????
        sum[j] -= 10;
        flag = 1;
      }
    }
    if(overflow){             //??????
      std::cout << "overflow" << std::endl;
      overflow = 0;
      continue;
    }
    for(j=0;j<102;j++){
      if(sum[101-j]!=0){
        sum_size = 101-j;
        break;
      }
    }
    for(j=sum_size;j>=0;j--){
      num = sum[j] + '0';
      std::cout << num;
    }
    std::cout << std::endl;
  }
}