Problem:
Score : 1200 points

Problem Statement

There are N arrays.
The length of each array is M and initially each array contains integers (1，2，...，M) in this order.

Mr. Takahashi has decided to perform Q operations on those N arrays.
For the i-th (1≤i≤Q) time, he performs the following operation.

Choose an arbitrary array from the N arrays and move the integer a_i (1≤a_i≤M) to the front of that array. For example, after performing the operation on a_i=2 and the array (5，4，3，2，1), this array becomes (2，5，4，3，1).

Mr. Takahashi wants to make N arrays exactly the same after performing the Q operations.
Determine if it is possible or not.

Constraints

2≤N≤10^5

2≤M≤10^5

1≤Q≤10^5

1≤a_i≤M

Input

The input is given from Standard Input in the following format:

N M
Q
a_1 a_2 ... a_Q

Output

Print Yes if it is possible to make N arrays exactly the same after performing the Q operations.
Otherwise, print No.

Sample Input 1

2 2
3
2 1 2

Sample Output 1

Yes

You can perform the operations as follows.

Sample Input 2

3 2
3
2 1 2

Sample Output 2

No

Sample Input 3

2 3
3
3 2 1

Sample Output 3

Yes

You can perform the operations as follows.

Sample Input 4

3 3
6
1 2 2 3 3 3

Sample Output 4

No

Solution in C (GCC 5.4.1) (judge verdict: Wrong Answer)

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

#define MOD 1000000007LL

int main(void) {
	int a[100010], b[100010], flag, i, j, k, M, N, P, Q;
	scanf("%d%d%d", &N, &M, &Q);
	for (i=0;i<Q;i++) scanf("%d", &a[i]);

	for (i=0;i<M;i++) b[i] = M-i;
	if (!memcmp(a, b, sizeof(int)*Q)) {
		printf("Yes\n");
		return 0;
	} else {
		P = 0;
		j = 1; k = M;
		for (i=0;i<Q;i++) {
			if (a[i] == j) continue;
			else if (a[i] == k) P++;
			else { flag=0; break; }
			if (P%N == 0) {
				j--; if (j==0) j += M;
				k--;
				flag = 1;
			}
		}
		if (P%N == 0 && flag == 1) printf("Yes\n");
		else printf("No\n");
	}

	return 0;
}