#include <iostream>
#include <locale.h>
#include <fstream>

using namespace std;

const int STR_LENGHT = 80;

bool readLine(ifstream& in, char* buffer)
{
	buffer[0] = 0;
	in.getline(buffer, STR_LENGHT + 1, '\n');
	if (in.fail())
	{
		if (buffer[0] > 0)
			cout << "Слишком длинная строка во входном файле" << endl;
		return false;
	}
	return true;
}

int Size(char* c)
{
	int n = 0;
	while (*c != 0) {
		if (isdigit(*c)) {
			while (isdigit(*c)) {
				n *= 10;
				n += (*c - '0');
				c++;
			}
			return n;
		}
	}
	return -3;
}

int SerchLen(char** arr, int i, int j)
{
	if (arr[i][j] == '0')
		return 0;
	arr[i][j] = '0';
	return 1 + SerchLen(arr, i, j + 1) + SerchLen(arr, i + 1, j) + SerchLen(arr, i, j - 1) + SerchLen(arr, i - 1, j);
}

int main()
{
	int Size(char* c);
	bool readLine(ifstream& in, char* buffer);
	int SerchLen(char** arr, int i, int j);
	setlocale(LC_ALL, "Russian");
	ifstream in("in.txt");
	if (!in.is_open())
	{
		cout << "Файла in.txt не существует" << endl;
		return -1;
	}

	ofstream out("out.txt");
	if (!out.is_open())
	{
		cout << "Файла out.txt не существует" << endl;
		return -2;
	}

	char buffer[STR_LENGHT + 1];
	int N, M;
	if (readLine(in, buffer)) {
		N = Size(buffer);
		M = Size(buffer);
	}
	char** arr = new char*[N + 2];
	for (int i = 0; i < N + 2; i++)
		arr[i] = new char[M + 2];
	int i = 0, j = 0, max = 0;
	for (j = 0; j < M + 2; j++) {
		arr[0][j] = '0';
		arr[N+1][j] = '0';
	}


	i = 1;
	while (readLine(in, buffer))
	{
		arr[i][0] = '0';
		for (j = 1; j <= M; j++)
			arr[i][j] = buffer[j-1];
		arr[i][M + 1] = '0';
		i++;
	}


	for (i = 1;i < N +1;i++)
		for (j = 1; j < M + 1; j++) {
			int a = SerchLen(arr, i, j);
			if (a > max)
				max = a;
		}

	out << "Ответ: " << max << endl;

	for (i = 0; i < N; i++)
		delete[] arr[i];
	system("pause");
	return 0;
}