#include <iostream>
#include <string>
#include <vector>

using namespace std;

const string alpha = "qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM";

vector<string> parse (string str)
{
	int pos;
	vector<string> vec;

	while (pos = str.find_first_not_of(alpha) != string::npos)
	{
		vec.push_back(str.substr(0, pos));
		str = str.substr(pos +1);
	}
	vec.push_back(str);
	return vec;
}

int max_length (vector<string> vec)
{
	int max_length = 0;
	for (int i = 0; i < vec.size(); ++i)
	{
		if(max_length < vec[i].length())
			max_length = vec[i].length();
	}
	return max_length;
}

int main()
{
	string str;
	//cin >> str;
	getline(cin, str);

	int result = 0;

	vector<string> arr_of_words = parse(str);
	result = max_length(arr_of_words);

	cout << result << endl;

	return 0;
}