#include <iostream>
#include <cstring>

using namespace std;

int main(int argc, const char *argv[]) {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    int T, res = 0;
    cin >> T;

    char str[40];
    while (T--) {
        cin >> str;

        bool chk[26] = {false}, flag = false;
        chk[str[0] - 'a'] = true;

        for (int i = 1; i < strlen(str); i++) {
            int ptr = str[i] - 'a', prev = str[i - 1] - 'a';

            if (chk[ptr] && ptr != prev) {
                flag = true;
            }
            chk[ptr] = true;
        }
        if (!flag) {
            res++;
        }
    }
    cout << res << endl;

    return 0;
}