#include<iostream>
#include<string>
using namespace std;

int main() {

	int num, count;
	num = count = 0;
	
	cin >> num;

	string* arr;
	arr = new string[num];

	char temp;

	for (int i = 0; i < num; i++) {
		cin >> arr[i];
		
		for (int j = 0; j < arr[i].size(); j++) {
			temp = arr[i].at(j);
			if (j == arr[i].size() - 1) {
				count++;
			}
			else if (arr[i].find(temp, j + 1) == -1) {
				continue;
			}
			else if (arr[i].find(temp, j + 1) != j + 1) {
				break;
			}
		}
	}

	cout << count << endl;

	delete[] arr;

	return 0;
}