#include <bits/stdc++.h>
using namespace std;
const int N = 5e4 + 5;
int n,m,cnt,p[N],pos[N];
bitset <N> k[N],f[N];
int main()
{
	scanf("%d%d",&n,&m);
	for(int i = 1;i <= n;i++)
	{
		scanf("%d",&p[i]);
		pos[p[i]] = i;
	}
	for(int i = 1;i <= n;i++) k[pos[i]] = k[pos[i - 1]],k[pos[i]][n - pos[i]] = 1;
	for(int i = 1;i <= n;i++) k[i] >>= (n - i + 1),f[i] = k[i];
	for(int j = 1;j <= 20;j++)
	{
		for(int i = n;i >= (1 << j);i--) f[i] &= f[i - (1 << (j - 1))];
		if(m & (1 << j))
		{
			for(int i = m;i <= n;i++)
				k[i] &= f[i - (m & ((1 << j) - 1))];
		}
	}
	for(int i = m;i <= n;i++) cnt += k[i].count();
	printf("%d\n",cnt);
	return 0;
}