#include<bits/stdc++.h>
using namespace std;
const int MAXN=5e4+5;
uint16_t n,m,a[MAXN];
uint16_t can[MAXN],ans[MAXN];
inline void check(uint16_t i,uint16_t mx){
    for(uint16_t len=1;len<=mx;len++){
        bool ok=a[i]<a[i+len];
        can[len]=(can[len]+1)*ok;
        ans[len]+=(can[len]>=m);
    }
}
signed main(){
    cin.tie(0);
    cout.tie(0);
    ios::sync_with_stdio(false);
    cin>>n>>m;
    for(uint16_t i=1;i<=n;i++)cin>>a[i];
    for(uint16_t i=1;i<=n;i++)check(i,min(n-m,n-i+1));
    int res=0;
    for(uint16_t i=1;i<=n;i++)res+=ans[i];
    cout<<res<<"\n";
}