import std.stdio,std.string,std.conv,std.bigint;
void main(){
	
	int set = to!int( readln().chomp() );
	for( int i=0; i<set ; i++ ){
		BigInt x = readln().chomp();
		BigInt y = readln().chomp();
		x += y;
		if( 	BigInt("1_0000000000_0000000000_0000000000_0000000000_0000000000_0000000000_0000000000_0000000000") <= x ){
			writeln("overflow");	
		}else{
			writeln( x );
		}
	}
}