#include <iostream>
#include <string>
using namespace std;
int main() {
	string L,R;int left,right,i,j,N;cin>>N;while (N--) {cin>>L>>R;left=L.length(),right=R.length();
		if (left>=right) {if (left>80) {cout<<"overflow"<<endl;continue;}R.resize(left);for (i=right-1,j=left-1;i>=0;i--,j--) R[j]=R[i];right=left;for (;j>=0;R[j--]='0');
		} else {if (right>80) {cout<<"overflow"<<endl;continue;}L.resize(right);for (i=right-1,j=left-1;j>=0;i--,j--) L[i]=L[j];left=right;for (;i>=0;L[i--]='0');}
		L[left]=0;for (i=left-1,j=0;i>=0;i--) {L[i]+=R[i]+j-48;if (L[i]>'9') j=1,L[i]-=10; else j=0;}i=L.length()+j;if (i>80) cout<<"overflow"<<endl; else {if (j) cout<<"1";cout<<L<<endl;}} return 0;}