#include<iostream>
#include<string>

using namespace std;

int maxLength(const int &len1, const int &len2) {
	return len1 > len2 ? len1 : len2;
}


int main()
{
	int N;

	cin >> N;

	for (int i = 0; i < N; i++) {
		string s1, s2;
		cin >> s1 >> s2;
		//cout << s1 << endl << s2 << endl;
		int len1 = s1.size();
		int len2 = s2.size();
		int max = maxLength(len1, len2);
		if (max > 80) {
			cout << "overflow" << endl;
			continue;
		}

		int str[100] = {0};
		int acc = 0;
		for (int i = 0; i < max; i++) {
			if (len1 > i && len2 > i) {
				str[i] = (s1[len1-1-i] - '0') + (s2[len2-1-i] - '0') + acc;
			}
			else if(len1 > i) {
				str[i] = (s1[len1 - 1 - i] - '0') + acc;
			}
			else if (len2 > i) {
				str[i] = (s2[len2 - 1 - i] - '0') + acc;
			}
			acc = 0;
			if (str[i] > 9) {
				acc = 1;
				str[i] %= 10;
			}
		}
		if (max == 80 && acc == 1) {
			cout << "overflow" << endl;
			continue;
		}

		str[max] = acc;

		for (int i = acc == 1? max:max-1; i > -1; i--) {
			cout << str[i];
		}
		cout << endl;
	}

	return 0;
}
