#include<bits/stdc++.h>
using namespace std;
int n,a[10001],dp[10001],m; 
int main(){
	cin>>n;
	for(int i=1;i<=n;i++){
		cin>>a[i];
	}
	for(int i=1;i<=n;i++){
		a[i]=1;
		for(int j=1;j<=i-1;j++){
			if(a[i]>a[j]){
				dp[i]=max(a[i]+1,a[i]);
			}
		}
		m=max(dp[i],dp[i+1]);
	}
	cout<<m;

	return 0;
}

/**************************************************************
	Problem: 1794
	User: caijiajie
	Language: C++
	Result: Wrong Answer
****************************************************************/