#include<iostream>
#include<string>

using namespace std;

int main(){
	int n,l1,l2,i;
	string a, b;
	char ans[80];
	int ia,ib,sum;
	cin>>n;
	while(n--){
		cin>>a>>b;
		if(a.length()>80 || b.length()>80){
			cout<<"overflow"<<endl;
			continue;
		}
		if(a.length()==80 || b.length()==80){
			if((int)a[0]-'0'+(int)b[0]-'0'>9){
				cout<<"overflow"<<endl;
				continue;
			}
		}
		if(a.length()<b.length()){
			swap(a,b);
		}
		l1=a.length();
		l2=b.length();
		for(i=0;i<80;i++)ans[i]=0;
		for(i=1;i<l2+1;i++){
			ia=(int)a[l1-i]-(int)'0';
			ib=(int)b[l2-i]-(int)'0';
			sum=ia+ib;
			ans[80-i]+=sum+'0';
		}
		for(i=l2+1;i<l1+1;i++){
			ans[80-i]=a[l1-i];
		}
		for(i=79;i>=0;i--){
			if(ans[i]-'0'>9 && ans[i]!=0){
				ans[i]=ans[i]-10;
				if(ans[i-1]==0)ans[i-1]+=1+'0';
				else ans[i-1]+=1;
			}
		}
		for(i=0;i<80;i++){
			if(ans[i]!=0){
				cout<<(int)ans[i]-'0';
			}
		}
		cout<<endl;
	}
	return 0;
}