#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<algorithm>
#include<string>
#include<iostream>
using namespace std;
int chrtoint(char a){
int i;
i=a-48;
 return i;
return 0;
}

int main(){
char n1[1000];
char n2[1000];
int rs[1000];
int c1, c2;

int i,j,m, cmax, sum,testcase;
scanf("%d",&testcase);
while(testcase--){
scanf("%s", &n1);
scanf("%s", &n2);
c1 = strlen(n1);
c2 = strlen(n2);

reverse(n1,n1+c1);
reverse(n2,n2+c2);

cmax = c1;
if(c1<c2){
cmax = c2;
}

m=0;
for(i=0; i< cmax; i++){
if(c1==c2 || (i < c1 && i < c2)){
sum = m+chrtoint(n1[i])+chrtoint(n2[i]);
}else if(i >=c1){
sum = m+chrtoint(n2[i]);
}else if(i >=c2){
sum = m+chrtoint(n1[i]);
}
if(sum>9){
m = 1;
rs[i] = sum-10;
}
else{
m=0;
rs[i] = sum;
}
}

if(m){
rs[i]=m;
i++;
}
if(i>80){
    printf("overflow\n");
    continue;
}
for(j=0; j < i; j++){
printf("%d", rs[i-j-1]);
}
}
return 0;
}