#include <bits/stdc++.h>
using namespace std;

const int MN = 1e5+5;
long long N, M, i, x, hsh, ans, lol, cnt[MN], pw[MN]={1};
map<long long,int> mp;

int main(){
    mp[0] ++;
    for(i=1;i<MN;i++) pw[i]=pw[i-1]*100003;
    for(scanf("%lld%lld",&N,&M),i=1;i<=N;i++){
        scanf("%lld",&x);
        cnt[x] ++;
        if(cnt[x] == 1) lol ++;
        if(lol == M){
            hsh = 0;
            for(int j=1;j<=M;j++){
                cnt[j] --;
                if(!cnt[j]) lol--;
                hsh += cnt[j]*pw[j];
            }
        }
        else{
            hsh -= (cnt[x]-1)*pw[x];
            hsh += cnt[x]*pw[x];
        }
        ans += mp[hsh];
        mp[hsh]++;
    }
    printf("%lld\n",ans);
    return 0;
}