C1. Increasing Subsequence (easy version)

Problem - 1157C1 - Codeforces

The only difference between problems C1 and C2 is that all values in input of problem C1 are distinct (this condition may be false for problem C2).

You are given a sequence aa consisting of nn integers. All these integers are distinct, each value from 11 to nn appears in the sequence exactly once.

You are making a sequence of moves. During each move you must take either the leftmost element of the sequence or the rightmost element of the sequence, write it down and remove it from the sequence. Your task is to write down a strictly increasing sequence, and among all such sequences you should take the longest (the length of the sequence is the number of elements in it).

For example, for the sequence [2,1,5,4,3][2,1,5,4,3] the answer is 44 (you take 22 and the sequence becomes [1,5,4,3][1,5,4,3], then you take the rightmost element 33 and the sequence becomes [1,5,4][1,5,4], then you take 44 and the sequence becomes [1,5][1,5] and then you take 55 and the sequence becomes [1][1], the obtained increasing sequence is [2,3,4,5][2,3,4,5]).

Input

The first line of the input contains one integer nn (1≤n≤2⋅1051≤n≤2⋅105) — the number of elements in aa.

The second line of the input contains nn integers a1,a2,…,ana1,a2,…,an (1≤ai≤n1≤ai≤n), where aiai is the ii-th element of aa. All these integers are pairwise distinct.

Output

In the first line of the output print kk — the maximum number of elements in a strictly increasing sequence you can obtain.

In the second line print a string ss of length kk, where the jj-th character of this string sjsj should be 'L' if you take the leftmost element during the jj-th move and 'R' otherwise. If there are multiple answers, you can print any.

Examples

input

Copy

5
2 1 5 4 3

output

Copy

4
LRRR

input

Copy

7
1 3 5 6 7 4 2

output

Copy

7
LRLRLLL

input

Copy

3
1 2 3

output

Copy

3
LLL

input

Copy

4
1 2 4 3

output

Copy

4
LLRL

Note

The first example is described in the problem statement.

题意：对一组数据，你可以取头或取尾来构成一个递增数列，取一个那么去掉原数组那个。

思路：用双指针，i从头往后，j从尾往后，若头和尾都大于上一个取出来的数st，那么取头和尾中最小的那个，如果头大于st，尾小于st，那么st=头，反之st=尾。结束条件是i >j或者头和尾都小于st，这样头和尾都不能取了。

#include
#include
using namespace std;
const int N=2e5+10;
int n;
int a[N];
char x;
queue<int>qu;
string s,str;
char st;
int main()
{
   cin>>n;
   int st=0;
   for(int i=1;i<=n;i++)cin>>a[i];
   int i=1,j=n;
  while(i<=j)
  {
      if(a[i]>=st&&a[j]>=st)
      {
          if(a[i]<=a[j])
          {
              st=a[i];
              i++;
              str+='L';
              
          }
          else
          {
               st=a[j];
              j--;
              str+='R';
             
          }
      }
      else if(a[i]>=st&&a[j]
      {
          st=a[i];
          i++;
          str+='L';
          
      }
      else if(a[i]=st)
      {
                st=a[j];
               j--;
              str+='R';
             
      }
      else if((a[i]j)
      {
          break;
      }
  }
  cout<size()<
   cout<
}

┭┮﹏┭┮，可算把这题给想出来了。