#include <cmath>
#include <iostream>
#include <string>
#include <cstdlib>

using namespace std;
int main(){
    string inp[2];
    int output[81],n;
    cin >> n;
    for(int j=0;j<n;j++){
        fill(output,output+81,0);
        cin >> inp[0] >> inp[1];
        if(inp[0].length()>80||inp[1].length()>80) cout << "overflow" << endl;
        else{
            for(int i=0;i<81;i++){
                if((int)inp[0].length()-1-i >= 0){
                    output[i]+=inp[0][inp[0].length()-1-i]-'0';
                }
                if((int)inp[1].length()-1-i >= 0){
                    output[i]+=inp[1][inp[1].length()-1-i]-'0';
                }
                if(output[i]>9){
                    output[i+1]+=output[i]/10;
                    output[i]%=10;
                }
            }
            if(output[80]>0) cout << "overflow" << endl;
            else{
                bool flag=false;
                for(int i=79;i>=0;i--){
                    if(!flag&&output[i]!=0) flag=true;
                    if(flag){
                        cout << output[i];
                    }
                }
                cout << endl;
            }
        }
    }
    return 0;
}
//90000000000000000000000000000000000000000000000000000000000000000000000000000000