//Aizu - 0015 : National Budget
#include<stdio.h>
#include<string.h>

int a[1005],b[1005];

int reverse(int *a,int l,int r)
{
	int i,t;
	for(i=l;i<=r/2;i++)
	{
		t=a[i];
		a[i]=a[l+r-i];
		a[l+r-i]=t;
	}
	return 0;
}

int main()
{
	int n,i,la,lb,lmax,c,tmp;
	char t;
	
	scanf("%d%*c",&n);		//霎灘?扈?焚?悟帥謗牙屓霓ヲ隨ヲ
	
	while(n--)		//隶。邂?	{
		la=0;		//貂?峺
		lb=0;
		c=0;
		memset(a,0,sizeof(a));
		memset(b,0,sizeof(b));
		
		while(1)	//蟄伜?謨ー蟄?		{
			t=getchar();
			if(t>='0'&&t<='9')
			{
				a[la]=t-'0';
				la++;
			}
			else if(t=='\n')
			{
				break;
			}
		}
		
		while(1)
		{
			t=getchar();
			if(t>='0'&&t<='9')
			{
				b[lb]=t-'0';
				lb++;
			}
			else if(t=='\n')
			{
				break;
			}
		}
		
		if(la>80||lb>80)		//霎灘?貅「蜃コ蛻、譁ュ
		{
			printf("overflow\n");
			return 0;
		}

		reverse(a,0,la-1);		//蜿榊髄
		reverse(b,0,lb-1);

		lmax=(la>lb)?la:lb;
		for(i=0;i<=lmax;i++)	//螟ァ謨ー蜉?ウ?		{
			tmp=a[i];
			a[i]=(tmp+b[i]+c)%10;
			c=(tmp+b[i]+c)/10;
		}

		for(i=lmax;i>=0;i--)	//霎灘?
		{
			if(a[i]!=0)
			{
				tmp=i;
				break;
			}
		}

		if(lmax+1>80)			//霎灘?貅「蜃コ蛻、譁ュ
		{
			printf("overflow\n");
			return 0;
		}

		for(i=tmp;i>=0;i--)
		{
			printf("%d",a[i]);
		}
		printf("\n");
	}
	return 0;
}