#include <bits/stdc++.h> 
using namespace std;
using ll =long long;
#define all(v) v.begin(),v.end()
 #define rep(i,a,b) for(int i=a;i<b;i++)
#define rrep(i,a,b) for(int i=a;i>=b;i--)

 int main() {
     ll N;cin>>N;
     
    vector<ll> P(N);
     vector<ll> note(N,0);
   
    for(ll i=0;i<N;i++) {
        cin>>P[i];
        note[P[i]-1]=i+1;

    }
  
  vector<ll> r(N+1);
  r[0]=0;
  for(ll i=0;i<N;i++)   {
      r[i+1]=r[i]+note[i];
  }
  ll ans=0;

  for(ll i=N;i>0;i--) {
      ans=max(ans,r[i-1]-note[i-1]);
  }
  cout<<ans<<endl;
 }