#include <bits/stdc++.h>
#define rep(i,l,n) for(int i=l;i<n;i++)
using namespace std;

/*int main(){
	int n;
	cin>>n;
	rep(i,0,n){
		string s1,s2;
		cin>>s1>>s2;

		if(s1.size()<s2.size()) swap(s1,s2);

		for(int j=s1.size()-1,k=s2.size()-1;j>=0;j--,k--){
			if(k>=0) s1[j]+=s2[k]-'0';
			if(s1[j]>'9'){
				s1[j]-=10;
				if(s2)
			}
			ans[j]=a%10;
			ans[j+1]=a/10;
			//cout<<" "<<j<<" "<<ans[j]<<endl;
		}
		if(ans[80]>0){
			cout<<"overflow"<<endl; return 0;
		}
		bool f=0;
		for(int i=80;i>=0;i--){
			if(f==0 && ans[i]>0){
				f=1; cout<<ans[i];
			}else if(f) cout<<ans[i];
		}
		cout<<endl;
	}
}*/

int main(){
    int n;
    cin>>n;
    rep(i,0,n){
        int ans[85]={},n1[81]={},n2[81]={};
        string s1,s2;
        cin>>s1>>s2;
        int sz1=s1.size(),sz2=s2.size();
 
        rep(j,0,sz1) n1[j]=s1[sz1-1-j]-'0';
        rep(j,0,sz2) n2[j]=s2[sz2-1-j]-'0';
 
        for(int j=0;j<81;j++){
            //cout<<"  "<<j<<" "<<n1[j]<<n2[j]<<endl;
            int a=ans[j]+n1[j]+n2[j];
            ans[j]=a%10;
            ans[j+1]=a/10;
            //cout<<" "<<j<<" "<<ans[j]<<endl;
        }
        if(ans[80]>0){
            cout<<"overflow"<<endl; return 0;
        }
        bool f=0;
        for(int i=80;i>=0;i--){
            if(f==0 && ans[i]>0){
                f=1; cout<<ans[i];
            }else if(f) cout<<ans[i];
        }
        cout<<endl;
    }
}