#include<cstdio>
#include<iostream>
#include<algorithm>
#include<cmath>
#include<vector>
using namespace std;
int main(){
    int n;
    scanf("%d",&n);
    for(int j=0;j<n;j++){
        string a,b;
        cin>>a>>b;
        int numa[100000]={0},numb[100000]={0};
        int flag=0;
        vector<int> sum;
        if(80<max(a.size(),b.size())){
            puts("overflow");
            goto exit;
        }
        for(int i=a.size()-1,k=0;0<=i;i--,k++)numa[k]=a[i]-'0';
        for(int i=b.size()-1,k=0;0<=i;i--,k++)numb[k]=b[i]-'0';
        for(int i=0;i<max(a.size(),b.size());i++){
            sum.push_back((numa[i]+numb[i])%10);
            numa[i+1]+=(numa[i]+numb[i])/10;
            if(i==max(a.size(),b.size())-1&&(numa[i]+numb[i])/10==1)printf("1");
        }
        if(80<sum.size())puts("overflow");
        else{
            for(int i=sum.size()-1;0<=i;i--)printf("%d",sum[i]);
            puts("");
        }
exit:
;
    }
    return 0;
}