#include<algorithm>
#include<string>
#include<iostream>
#include<cstdio>

using namespace std;
int main(){
	int n,l,m,c;
	string a,b;
	cin >> n;
	for(int i=0;i<n;i++){
		char s[90] = {0};
		cin >> a;
		cin >> b;
		reverse(a.begin(),a.end());
		reverse(b.begin(),b.end());
		if(a.length()<b.length())swap(a,b);
		l = a.length();
		m = b.length();
		c=0;
		for(int j=0;j<l;j++){
			int o=a[j]-'0' + c;
			if(j<m)o += b[j]-'0';
			c = o>9;
			s[j] = o%10 + '0';
		}
		if(c>0)s[l++]='1';
		reverse(s,s+l);
		if(l>80)cout << "overflow" << endl;
		else printf("%s\n",s);
	}
	return 0;
}