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

int a[85],b[85];

int reverse(int *p,int length)
{
	int i,t;

	for(i=1;i<=length/2;i++)
	{
		t=p[i];
		p[i]=p[length+1-i];
		p[length+1-i]=t;
	}

	return 0;
}

int main()
{
	int N,i,la,lb,lmax,carry,t;
	char ch;
	
	scanf("%d%*c",&N);
	
	while(N--)
	{
		la=0;
		lb=0;
		carry=0;
		memset(a,0,sizeof(a));
		memset(b,0,sizeof(b));

		while(1)
		{
			ch=getchar();

			if(ch>='0'&&ch<='9')
			{
				la++;
				a[la]=ch-'0';
			}

			else if(ch=='\n')
			{
				break;
			}
		}
	
		while(1)
		{
			ch=getchar();
			
			if(ch>='0'&&ch<='9')
			{
				lb++;
				b[lb]=ch-'0';
			}

			else if(ch=='\n')
			{
				break;
			}
		}
	
		if(la>80||lb>80)
		{
			printf("overflow\n");
			continue;
		}

		reverse(a,la);
		reverse(b,lb);

		lmax=la>lb?la:lb;

		for(i=1;i<=lmax+1;i++)
		{
			t=a[i];
			a[i]=(t+b[i]+carry)%10;
			carry=(t+b[i]+carry)/10;
		}

		for(i=lmax+1;i>=1;i--)
		{
			if(a[i]!=0)
			{
				t=i;
				break;
			}
		}

		if(t>80)
		{
			printf("overflow\n");
			continue;
		}

		if(i==0)
		{
			printf("0\n");
			continue;
		}

		for(i=t;i>=1;i--)
		{
			printf("%d",a[i]);
		}

		printf("\n");
	}
	
	return 0;
}