#include <iostream>
using namespace std;
int tr[2003][3], cnt = 1;
void ins(string s) {
    int now = 1;
    for (auto i : s) {
        if (i == '?') i = '2';
        if (!tr[now][i - '0']) {
            cnt++;
            tr[now][i - '0'] = cnt;
        }
        now = tr[now][i - '0'];
    }
}
int main() {
    freopen("lowtea.in", "r", stdin);
    freopen("lowtea.out", "w", stdout);
    int n;
    cin >> n;
    for (int i = 1; i <= n; i++) {
        string s;
        cin >> s;
        ins(s);
    }
    cout << cnt;
    return 0;
}
/*#include <iostream>
using namespace std;
int tr[2003][3], cnt = 1;
void ins(string s) {
    int now = 1;
    for (auto i : s) {
        if (i == '?') i = '2';
        if (!tr[now][i - '0']) {
            cnt++;
            tr[now][i - '0'] = cnt;
        }
        now = tr[now][i - '0'];
    }
}
int ans = 0;
int sz[2003];
void dfs(int x) {
    sz[x] = 1;
    for (int i = 0; i <= 2; i++) {
        if (tr[x][i]) {
            dfs(tr[x][i]);
            sz[x] += tr[x][i];
        }
    }
}
int c = 0;
void f(int x, int y) {
    for (int i = 0; i <= 2; i++) {
        if (!tr[x][i] && tr[y][i]) {
            c += sz[tr[y][i]];
        }
    }
}
void s(int x) {
    if (tr[x][2]) {
    }
}
int main() {
    int n;
    cin >> n;
    for (int i = 1; i <= n; i++) {
        string s;
        cin >> s;
        ins(s);
    }
    cout << cnt;
    return 0;
}*/