#include <map>
#include <set>
#include <list>
#include <cmath>
#include <ctime>
#include <deque>
#include <queue>
#include <stack>
#include <bitset>
#include <cstdio>
#include <limits>
#include <vector>
#include <cstdlib>
#include <numeric>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <functional> 
#include <iomanip>
#include <unordered_map>
#include <memory.h>
#include <unordered_set>
#include <fstream>

using namespace std;

int A[200001];

int main(void)
{
	cin.tie(0);
	ios::sync_with_stdio(false);
	
	int n;

	cin >> n;

	for (int i = 1; i <= n; i++)
	{
		cin >> A[i];
	}

	int cnt = 0;

	for (int i = n; i >= 1; i--)
	{
		if (A[i] == 0)
		{
			continue;
		}
		if (A[i] > i)
		{
			cout << "No" << '\n';
			return 0;
		}
		int x = (cnt + A[i]) % i;
		if (x != 0)
		{
			cout << "No" << '\n';
			return 0;
		}
		cnt++;
	}
	cout << "Yes" << '\n';
	return 0;
}