Problem:
National Budget

A country has a budget of more than 81 trillion yen. We want to process such data, but conventional integer type which uses signed 32 bit can represent up to 2,147,483,647.

Your task is to write a program which reads two integers (more than or equal to zero), and prints a sum of these integers.

If given integers or the sum have more than 80 digits, print "overflow".

Input

Input consists of several datasets. In the first line, the number of datasets N (1 ≤ N ≤ 50) is given. Each dataset consists of 2 lines:

The first integer
The second integer

The integer has at most 100 digits.

Output

For each dataset, print the sum of given integers in a line.

Sample Input

6
1000
800
9999999999999999999999999999999999999999
1
99999999999999999999999999999999999999999999999999999999999999999999999999999999
1
99999999999999999999999999999999999999999999999999999999999999999999999999999999
0
100000000000000000000000000000000000000000000000000000000000000000000000000000000
1
100000000000000000000000000000000000000000000000000000000000000000000000000000000
100000000000000000000000000000000000000000000000000000000000000000000000000000000

Output for the Sample Input

1800
10000000000000000000000000000000000000000
overflow
99999999999999999999999999999999999999999999999999999999999999999999999999999999
overflow
overflow

Solution in JAVA (judge verdict: Accepted)

import java.io.*;
import java.math.BigInteger;
import java.util.*;

/**
 * @author yoshikyoto
 */
class Main{
	static final boolean DEBUG = false;
	static Scanner sc = new Scanner(new InputStreamReader(System.in));
	static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	
	public static void main(String args[]) throws Exception{
		int n = readInt();
		for(int i = 0; i < n; i++){
			String s1 = readLine();
			String s2 = readLine();
			if(s1.length() > 80 || s2.length() > 80){
				p("overflow");
				continue;
			}
			BigInteger bi1 = new BigInteger(s1);
			BigInteger bi2 = new BigInteger(s2);
			BigInteger bi = bi1.add(bi2);
			String s = bi.toString();
			if(s.length() > 80){
				p("overflow");
				continue;
			}
			p(s);
		}
	}
		

	public static int[] readIntMap() throws IOException{return parseInt(readLine().split(" "));}
	public static String readLine() throws IOException{return br.readLine();}
	public static int readInt() throws IOException{return Integer.parseInt(br.readLine());}
	public static void pa(Object[] arr){System.out.println(Arrays.toString(arr));}
	public static void pa(int[] arr){System.out.println(Arrays.toString(arr));}
	public static void pa(double[] arr){System.out.println(Arrays.toString(arr));}
	public static void pa(boolean[] arr){System.out.println(Arrays.toString(arr));}
	public static void p(Object o){System.out.println(o.toString());}
	public static void d(Object o){if(DEBUG)System.out.println(o.toString());}
	public static void da(int[] arr){if(DEBUG)System.out.println(Arrays.toString(arr));}
	public static void sort(int[] a){Arrays.sort(a);}
	public static int[] parseInt(String[] arr){
		int[] res = new int[arr.length];
		for(int i = 0; i < arr.length; i++)res[i] = Integer.parseInt(arr[i]);
		return res;
	}
	public static boolean[] parseBool(String[] arr){
		int[] t = parseInt(arr);
		boolean[] res = new boolean[t.length];
		for(int i = 0; i < t.length; i++){
			if(t[i] == 1){
				res[i] = true;
			}else{
				res[i] = false;
			}
		}
		return res;
	}
	public static int parseInt(Object o){return Integer.parseInt(o.toString());}
	public static int digit(int n){return String.valueOf(n).length();}
	public static String reverse(String s){
		StringBuffer sb = new StringBuffer(s);
		return sb.reverse().toString();
	}
	
}

/**
 * 整数を数え上げたりするクラス
 * Prime.calc(int n) でnまでエラトステネスの篩を実行。
 * @author yoshikyoto
 * @param a[i] iが素数の時true
 * @param count[i] i以下の素数の数
 */
class Prime{
	static boolean[] a;
	static int[] count;
	public static void calc(int n){
		a = new boolean[n+1];
		a[0] = false; a[1] = false;
		for(int i = 2; i <= n; i++) a[i] = true;
		// ふるい
		for(int i = 2; i < (n - 3) / 2; i++)
			if(a[i]) for(int j = 2; j * i <= n; j++)
					a[j * i] = false;
		
		// 数え上げ
		count = new int[n+1];
		count[0] = 0;
		for(int i = 1; i <= n; i++){
			int gain = 0;
			if(a[i]) gain = 1;
			count[i] = count[i-1] + gain;
		}
	}
}

class AI extends ArrayList<Integer>{}
class SI extends Stack<Integer>{}

class HI<E> extends HashMap<E, Integer>{
	ArrayList<E> keyArray = new ArrayList<E>();
	public void add(E key){add(key, 1);}
	public void add(E key, Integer value){
		if(containsKey(key)){value += get(key);
		}else{keyArray.add(key);}
		put(key, value);
	}
}