#include <bits/stdc++.h>
using namespace std;

class bigint {
	deque<uint8_t> val;

public:
	bigint( const string& s ) {
		for( auto c: s ) {
			val.push_front( c - '0' );
		}
	}

	void add( const bigint& b ) {
		int x = 0;
		int i = 0;

		for( ; i < b.val.size(); ++i ) {
			if( i >= val.size() ) {
				val.push_back( 0 );
			}

			x += val[i] + b.val[i];
			val[i] = x % 10;
			x /= 10;
		}

		for( ; x > 0; ++i ) {
			if( i >= val.size() ) {
				val.push_back( 0 );
			}

			x += val[i];
			val[i] = x % 10;
			x /= 10;
		}
	}

	int length() const {
		return (int)val.size();
	}

	void print() const {
		for( int i = (int)val.size()-1; i >= 0; --i ) {
			cout << (int)val[i];
		}

		cout << '\n';
	}
};

int main() {
	ios_base::sync_with_stdio( false );

	int N;
	cin >> N;

	for( int i = 0; i<N; ++i ) {
		string a, b;
		cin >> a >> b;

		bigint x( a );
		x.add( b );

		if( x.length() <= 80 ) {
			x.print();
		}
		else {
			cout << "overflow" << '\n';
		}
	}
}

