#include<iostream>
#include<vector>

using namespace std;

int main()
{
	int n, a;
	vector<int>numbers;

	cin >> n;
	for (int i = 0; i < n; i++)
	{
		cin >> a;
		numbers.push_back(a);
	}

	int continu_num = 1;
	int max_continu_num = 1;
	for (int i = 0; i < numbers.size() - 1; i++)
	{
		if (numbers[i] + 1 == numbers[i + 1])
		{
			continu_num++;
			if (continu_num > max_continu_num)
			{
				max_continu_num = continu_num;
			}
		}
		else
		{
			continu_num = 1;
		}
	}
	cout << max_continu_num << endl;


	return 0;
}

下载次数用完了,看不到第四个点的信息,目前想不通哪里出错了