#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <utility>
#include <set>
#include <queue>
#include <cmath>
using namespace std;
typedef long long ll;
#define rep(i, n) for (int i=0;i < (int)(n);i++)

int main(){
    ll n;
    cin >> n;
    ll ans = 0;
    if (n == 1){
        cout << 0 << endl;
        return 0;
    }
    rep(i,n){
        ll x;
        cin >> x;
        if (x == n){
            ans -= (i+1);
        }
        else{
            ans += (i+1);
        }
    }
    cout << ans << endl;

    return 0;
}