#include<iostream>
#include<vector>
#include<cmath>

using namespace std;

typedef long long ll;

vector<int>nu[100001];
bool flag[100001];

int main()
{
	int n;
	cin >> n;
	for (int i = 1; i <= n; i++)
	{
		int su;
		cin >> su;
		nu[su].push_back(i);
	}
	int su = n;
	int r = n;
	ll an = 0;
	for (int i = 1; i <= n; i++)
	{
		for (auto j : nu[i - 1])
		{
			flag[j] = 1;
			su--;
		}
		while (r >= 1 && flag[r])
		{
			r--;
		}
		if (r >= 1)
		{
			an += 1ll*su * r;
		}
	}
	cout << an << endl;
	return 0;
}