import std.stdio;
import std.array;//split
import std.conv;//to
import std.string;//chomp
import std.bigint;

void main(){
    string[] input = split(readln());
    int n= to!int(input[0]);
    while(n--){
        BigInt a = BigInt(chomp(readln()));
        BigInt b = BigInt(chomp(readln()));
        BigInt c = a+b;
        if(c<BigInt("100000000000000000000000000000000000000000000000000000000000000000000000000000000"))
            writeln(c);
        else writeln("overflow");
    }
}