#include<stdio.h>
#include<string.h>
#include<iostream>

int count(int data[]){
	int cnt = 0,i=0;
	while(1){
		if(data[i] == 10)break;
		cnt++;
		i++;
	}
	return cnt;
}

void sum(char data1[],char data2[],int ans[]){
	int i;
	for(i = 0;i < strlen(data1) || i < strlen(data2);i++){
		int st1,st2,st3;
		if(i >= strlen(data1)){
			st1 = 0;
		}else{
			st1 = data1[strlen(data1)-i-1];
			st1 = st1 - 48;
		}
		if(i >= strlen(data2)){
			st2 = 0;
		}else{
			st2 = data2[strlen(data2)-i-1];
			st2 = st2 - 48;
		}
		st3 = st1 + st2;
		if(st3 >= 10){
			if(ans[i] == 1){
				ans[i] = st3 - 9;
				ans[i + 1] = 1;
			}else{
				ans[i] = st3 - 10;
				ans[i + 1] = 1;
			}
		}else{
			if(ans[i] == 1){
				if(st3 == 9){
					ans[i] = 0;
					ans[i + 1] = 1;
				}else{
					ans[i] = st3 + 1;
				}
			}else{
				ans[i] = st3;
			}
		}
	}
	if(ans[i] == 1){
		ans[i + 1] = 10;
	}else{
		ans[i] = 10;
	}
}

void reverse(int ans[]){
	if(count(ans) > 80){
		std::cout << "overflow" << std::endl;
	}else{
		int i;
		for(i = count(ans)-1;i >= 0;i--){
			printf("%d",ans[i]);
		}
	}
}

int main(void){
	int cnt,i;
	scanf("%d",&cnt);
	for(i = 0;i < cnt;i++){
		int ans[82];
		char data1[82],data2[82];
		scanf("%s",data1);
		scanf("%s",data2);
		if(strlen(data1) > 80 || strlen(data2) > 80){
			std::cout << "overflow" << std::endl;
		}else{
			sum(data1,data2,ans);
			reverse(ans);
		}
		printf("\n");
	}
	return 0;
}