#include<string>
#include<iostream>
#include<algorithm>
using namespace std;
string a,b,sum;
void check(int z,int x);
int A,B;
int main(void){
    int n;
    cin>>n;
    while(n--){
        a="",b="",sum="";
        cin>>a>>b;
        A=a.length(),B=b.length();
        reverse(a.begin(),a.end()),reverse(b.begin(),b.end());
        if(A<B)swap(A,B),swap(a,b);
        for(int i=0;i<=A-B;i++)b+="0";
        check(0,0);
        if(sum.length()>80){
            sum="overflow";
            goto end;
        }
        reverse(sum.begin(),sum.end());
        end:;
        cout<<sum<<endl;
    }
    return 0;
}
void check(int z,int x){
    int i;
    if(a[z]==0)a[z]='0';
    if(b[z]==0)b[z]='0';
    if(z==81||(z>A&&z>B&&x==1)||(z>=A&&z>=B&&x==0)){
            x=0;
            return;
    }
    i=(int)a[z]-'0' + (int)b[z]-'0' + x,x=0;
    if(i>=10)x=1,i-=10;
    sum+=i+'0';
    check(z+1,x);
}