#include <iostream>
#include <string>
using namespace std;

int main()
{
	int n;
	cin >> n;
	for (int i = 0; i < n; ++i)
	{
		int A[150] = {},B[150] = {},C[150] = {};
		string inA,inB;
		cin >> inA >> inB;
		for (int j = 0; j < inA.size(); ++j)
			A[inA.size()-j] = (int)(inA[j]-'0');
		for (int j = 0; j < inB.size(); ++j)
			B[inB.size()-j] = (int)(inB[j]-'0');
		int keta = 0;
		for (int j = 1; j < 150; ++j)
		{
			C[j] += A[j] + B[j];
			if(C[j] >= 10)
			{
				C[j+1] += C[j]/10;
				C[j] = C[j]%10;
			}
			if(C[j] != 0)
				keta = j;
		}
		cout << keta << endl;
		if(keta > 80)
			cout << "overflow" << endl;
		else
		{
			bool haji = 0;
			for (int j = 149; j > 0; --j)
			{
				if(C[j] != 0)
					haji = 1;
				if(haji)
				{
					cout << C[j];
				}
			}
			cout << endl;
		}
	}
}