rayon6

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

using namespace std;

bool find(vector <string> &c, string s) {
    for (int i = 0; i < c.size(); i++)
        if (c[i] == s)
            return true;

    return false;
}

int main() {

    int k, n;

    cin >> k >> n;

    vector<string> c;
    set <char> set1;
    set <char> set2;

    for (int i = 0; i < n; i++) {
        string s;
        cin >> s;
        c.push_back(s);
    }

    string str1, str2;
    string s1;
    string s2;
    cin >> str1 >> str2;

    set1.insert(str1.begin(), str1.end());
    set2.insert(str2.begin(), str2.end());

    if (str1.size() != str2.size() || set1 != set2) {
        cout << "NO";
        return 0;
    }

    for (char c1 = 'a'; c1 < 'j'; c1++) {
        for (char c2 = c1 + 1; c2 < 'j'; c2++) {
            string s = { c1, c2 };
            if (find(c, s))
                continue;
            else {
                s1 = "";
                s2 = "";
                for (int i = 0; i < str1.size(); i++) {
                    if (str1[i] == c1 || str1[i] == c2)
                        s1.push_back(str1[i]);
                    if (str2[i] == c1 || str2[i] == c2)
                        s2.push_back(str2[i]);
                }

                if (s1 != s2) {
                    cout << "No";
                    return 0;
                }
            }
        }
    }

    cout << "Yes";



    return 0;
}