#include<bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
using mint=modint998244353; //1000000007;
using ll=long long;
using pp=pair<int,int>;
#define sr string 
#define vc vector
#define fi first
#define se second
#define rep(i,n) for(int i=0;i<(int)n;i++)
#define pb push_back
#define all(v) v.begin(),v.end()
#define pque priority_queue
#define bpc(a) __builtin_popcount(a)
int main(){
  int n;cin>>n;
  ll ans=0;
  vc<int>v(n); rep(i,n)cin>>v[i]; rep(i,n)v[i]--;
  vc<int>r(n); rep(i,n)r[v[i]]=i;
  ll now=(ll)n*(n+1)/2;
  for(int i=n-1;i>=0;i--){
    now-=r[i]+1;
    ans=max(ans,now-(r[i]+1));
  }
  cout<<ans;
}