#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
int main(){
	int d;
	for(cin>>d;d>0;d--){
		char ans[100];
		char n1[100];
		char n2[100];
		for(int i=0;i<=100;i++)ans[i]=n1[i]=n2[i]='0';
		scanf("%s",n1);
		scanf("%s",n2);
		int h1=strlen(n1)-1;
		int h2=strlen(n2)-1;
		int limit=max(h1,h2);
		int i;
		//		cout<<"h1(n1):"<<h1<<endl;
		//	cout<<"h2(n2):"<<h2<<endl;
		//cout<<"limit:"<<limit<<endl;
		bool flg=false;
		for( i=0;i<=limit;i++,h1--,h2--){
			flg=false;
			int n1_tmp=0;
			int n2_tmp=0;
			if(h1>=0){
				n1_tmp=n1[h1]-'0';
			}
			if(h2>=0){
				n2_tmp=n2[h2]-'0';
			}
			int sum=n1_tmp+n2_tmp;
			if(sum>=10){
				ans[i+1]=ans[i+1]+1;
				sum=sum%10;
				flg=true;
			}
			ans[i]+=sum;
			if(ans[i]>'9'){
				ans[i]=ans[i]-(10);
				ans[i+1]+=1;
				flg=true;
			}
		}
		if(flg){
			i++;
		}
		ans[i]='\0';
		if(i>80)cout<<"overflow"<<endl;
		else{
			for(i--;i>=0;i--){
				cout<<ans[i];
			}
			cout<<endl;
		}
//		cout<<"size:"<<strlen(ans)<<endl;
	}


	return 0;
}