#include <bits/stdc++.h>
using namespace std;
int a[30000];
int b[30000];
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int n,m;
cin >> n >> m;//输入n,m;
for (int i = 1; i <= n; i)
{
cin >> a[i];
}
int ans = 0;
int res;
for (int i = 2; i < n; i)
{
res = 0;
if (a[i]<a[i-1])
{
res;
}
while(i+1<n&&a[i+1] == a[i]){
i;
}
if (a[i+1] >a[i])
{
res++;
}
if (res == 2)
{
ans++;
}
}
cout << ans;
return 0;
}
