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

int sum(char a[],char b[],int as,int bs,char c[]){
	int cs = (as>bs) ? as + 1 : bs + 1;
	int size = cs;
	while(as >=0 && bs >=0){
		c[cs] = a[as] + b[bs];
		if(c[cs]>9){
			c[cs] -= 10;
			c[cs-1] += 1;
		}
		as--;bs--;cs--;
	}
	while(as >=0){
		c[cs] += a[as];
		if(c[cs]>9){
			c[cs] -= 10;
			c[cs-1] += 1;
		}
		as--;cs--;
	}
	while(bs >=0){
		c[cs] += b[bs--];
		if(c[cs]>9){
			c[cs] -= 10;
			c[cs-1] += 1;
		}
		cs--;
	}
	return (c[0]>0) ? size + 1 : size;
}

int main(){
	char a[256],b[256],c[256];
	bool flag = true;
	int len1,len2,len3,n;
	scanf("%d",&n);
	while(n--){
		scanf("%s",a);
		scanf("%s",b);
		len1 = strlen(a);
		len2 = strlen(b);
		if(len1 > 80 || len2 >80){
			printf("overflow\n");
			continue;
		}
		for(int i=0;i<len1;i++) a[i] -= 0x30;
		for(int i=0;i<len2;i++) b[i] -= 0x30;
		for(int i=0;i<256;i++)  c[i] = 0;
		len3 = sum(a,b,len1-1,len2-1,c);
		if(len3>80){
			printf("overflow\n");
			continue;
		}
		if(c[0]>0) for(int i=0;i<len3;i++) printf("%d",c[i]);
		else for(int i=1;i<=len3;i++) printf("%d",c[i]);
		printf("\n");
	}
	return 0;
}