import std.stdio;
import std.string;
import std.conv;
import std.algorithm;

void main(){

    int n;
    readf("%d\n",&n);
    for(int i=0;i<n;i++){
	string s1,s2,res;
	s1 = chomp(readln());
	s2 = chomp(readln());
	res = "";
	int x = to!int(s1.length-1);
	int y = to!int(s2.length-1);
	if( y > x) {
	    swap(s1,s2);
	    swap(x,y);
	}
	int add = 0;
	while(x >= 0 || add > 0){
	    int sum = 0;
	    if(y >= 0)
		sum = to!int(s1[x] - '0') + to!int(s2[y] - '0');
	    else if(x >= 0)
		sum = to!int(s1[x] - '0');
	    else 
		sum = 0;
	    if( sum + add > 9){
		    res = to!string((sum + add)%10) ~ res;
		    add = 1;
	    }else{
		res = to!string(sum + add) ~ res;
		add = 0;
	    }
	    if(x >= 0) x--;
	    if(y >= 0) y--;
	}
	if(res.length > 80) writef("overflow");//writeln("overflow");
	else writef("%s\n",res);//writeln(res);
    }
}