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

#define MAX_DIGIT 80


void add(char *buf1, char *buf2){
	int len1 = strlen(buf1);
	if(len1 > MAX_DIGIT){
		printf("overflow\n");
		return;
	}
	int len2 = strlen(buf2);
	if(len2 > MAX_DIGIT){
		printf("overflow\n");
		return;
	}
	
	int big1[MAX_DIGIT + 1] = {}, big2[MAX_DIGIT + 1] = {};
	
	for(int i = 0; i < len1; i++){
		big1[len1 - i - 1] = buf1[i] - 48;
	}
	for(int i = 0; i < len2; i++){
		big2[len2 - i - 1] = buf2[i] - 48;
	}
	
	int len = (len1 > len2) ? len1 : len2;
	for(int i = 0; i < len; i++){
		big1[i] += big2[i];
		if(big1[i] >= 10){
			big1[i + 1]++;
			big1[i] -= 10;
		}
	}
	
	int j = len;
	for(; j >= 0; j--){
		if(big1[j] > 0){
			break;
		}
	}
	if(j >= MAX_DIGIT){
		printf("overflow\n");
		return;
	}
	for(; j >= 0; j--){
		printf("%d", big1[j]);
	}
	printf("\n");
}

int main(){
	int n;
	
	scanf("%d", &n);
	for(int i = 0; i < n; i++){
		char buf1[101], buf2[101];
		scanf("%s", buf1);
		scanf("%s", buf2);
		add(buf1, buf2);
	}
	
	return 0;
}