#include <iostream>
#include <vector>
#include <string>

using namespace std;

int main(){
    string a, b;
    vector<int> ans;

    int n, num, ai, bi, c = 0;

    bool flag;

    cin >> n;
    while (n--){
	cin >> a >> b;
	flag = false;

	for (int j = 0; j < 100; j++){
	    num = 0;
	    ai = a.size() - j - 1;
	    bi = b.size() - j - 1;
	    if (ai < 0 && bi < 0 && c == 0) break;

	    if (ai >= 0) num += a[ai] - 48;
	    if (bi >= 0) num += b[bi] - 48;
	    ans.push_back((num+c) % 10);
	    if (num + c >= 10) c = 1;
	    else c = 0;
	}
	if (ans.size() > 80) flag = true;

	if (flag) puts("overflow");
	else {
	    for (int j = ans.size() - 1; j >= 0; --j) printf("%d\n", ans[j]);
	}
	ans.clear();
    }
    return 0;
}