Codeforces Round #411 A. Fake NP

A. Fake NP
time limit per test  
1 second
memory limit per test  
256 megabytes
 

Tavak and Seyyed are good friends. Seyyed is very funny and he told Tavak to solve the following problem instead of longest-path.

You are given l and r. For all integers from l to r, inclusive, we wrote down all of their integer divisors except 1. Find the integer that we wrote down the maximum number of times.

Solve the problem to show that it's not a NP problem.

Input

The first line contains two integers l and r (2 ≤ l ≤ r ≤ 109).

Output

Print single integer, the integer that appears maximum number of times in the divisors.

If there are multiple answers, print any of them.

 
input
19 29
output
2
input
3 6
output
3
Note:

The first example: from 19 to 29 these numbers are divisible by 2: {20, 22, 24, 26, 28}.

The second example: from 3 to 6 these numbers are divisible by 3: {3, 6}.

 

题目大意:

     给定一个范围,输出一个整数x,(使得这个范围内能整除x的整数个数最多)

解题思路:

     刚开始写的时候没想辣么多,处理超级复杂,之后仔细想想其实只有两种情况

     1、当l和r相同时任意输出一个。  2、当l和r不同时输出2(所有的偶数都能被2整除)

AC代码:

 1 #include <stdio.h>
 2 #include <string.h>
 3 #include <math.h>
 4 #include <stdlib.h>
 5 #include <algorithm>
 6 using namespace std;
 7 
 8 int main ()
 9 {
10     int l,r;
11     while (~scanf("%d %d",&l,&r))
12     {
13         if (l == r)
14             printf("%d\n",l);
15         else
16             printf("2\n");
17     }
18     return 0;
19 }

 

posted @ 2017-05-16 13:31  gaoyanliang  阅读(239)  评论(0编辑  收藏  举报