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

int main()
{
	string s1,s2;
	int n;
	cin>>n;
	while(n--)
	{
		cin>>s1>>s2;
		if(s1.size()>81||s2.size()>81) cout<<"overflow"<<endl;
		else
		{
			int ans[90],now=1;
			int size1=s1.size(),size2=s2.size();
			bool over=false;
			while(1)
			{
				ans[now-1]=0;
				if(size1==0&&size2==0&&!over) break;
				
				if(size1>0)
				{
					ans[now-1]+=s1[size1-1]-'0';
					size1--;
				}
				if(size2>0)
				{
					ans[now-1]+=s2[size2-1]-'0';
					size2--;
				}

				if(over)
				{
					ans[now-1]+=1;
					over=false;
				}
				if(ans[now-1]>=10)
				{
					ans[now-1]%=10;
					over=true;
				}
				now++;
			}
			if(now>81) cout<<"overflow"<<endl;
			else
			{
				for(int i=now-2;i>=0;i--)
				{
					cout<<ans[i];
				}
				cout<<endl;
			}
		}
	}
	return 0;
}