#include <cstdio>
#include <cstring>
#define MAX_NUM 32767

using namespace std;

void array_add(int *a,int *b){
	int i;
	for(i = MAX_NUM - 1;i > 0;i--){
		a[i] = a[i] + b[i];
		a[i - 1] = a[i - 1] + a[i] / 10;
		a[i] %= 10;
	}
}

int main(void){
	int n, i, j, len1,len2, val1[MAX_NUM], val2[MAX_NUM];
	char c;
	scanf("%d%*c",&n);
	for(i = 0;i < n;i++){
		for(j = 0;(c = getchar()) != '\n';j++){
			val1[j] = c - '0';
		}
		len1 = j;
		for(j = 0;(c = getchar()) != '\n';j++){
			val2[j] = c - '0';
		}
		len2 = j;
		for(j = MAX_NUM - 1;j > MAX_NUM - 1 - len1;j--){
			val1[j] = val1[len1 - 1 + (j - (MAX_NUM - 1))];
		}
		for(;j >= 0;j--){
			val1[j] = 0;
		}
		val1[MAX_NUM] = 0;
		for(j = MAX_NUM - 1;j > MAX_NUM - 1 - len2;j--){
			val2[j] = val2[len2 - 1 + (j - (MAX_NUM - 1))];
		}
		for(;j >= 0;j--){
			val2[j] = 0;
		}
		array_add(val1,val2);
		for(j = 0;val1[j] == 0 && j < MAX_NUM;j++);
		if(j <= MAX_NUM - 81)
			printf("overflow");
		else if(j == MAX_NUM)
			printf("0");
		else{
		for(;j < MAX_NUM;j++){
			printf("%d",val1[j]);
		}
		}
		printf("\n");
	}
	return 0;
}