#include "bits/stdc++.h"
#define rep(i, j) for (int i = 0; i < j; i++)
#define srep(i, j, k) for (int i = j; i < k; i++)
using namespace std;
using ll = long long;
using P = pair<int, int>;
using ull = unsigned long long;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }

//�G���g�X�e�l�X���
vector<int> estora(vector<int> num) {
    int sel = 0;
    while (sel < num.size()) {
        int d = num[sel];
        for (int i = 0; i < num.size(); i++) {
            if (num[i] % d == 0 && num[i] != d && d != 1) {
                num.erase(num.begin() + i);
                i--;
            }
        }
        sel++;
    }
    return num;
}
/*���C�u�����ő����*/
//���[�O���b�h�̌ݏ��@
int gcd(int x, int y) {
    int num[3];
    num[0] = (x > y) ? x : y;
    num[1] = (x <= y) ? x : y;
    num[2] = num[0] % num[1];

    while (num[2]) {
        num[0] = num[1];
        num[1] = num[2];
        num[2] = num[0] % num[1];
    }

    return num[1];
}

/*�f��������*/
//���색�C�u����
//i����ɑf���ɂ��Ă����Ȃ��Ƃ��܂��ł��Ȃ�&&�v�Z�ʃ��o�C
//�G�X�g���l�X��⿂őf����U����Ă����K�v�������肻��
vector<ll> fac(ll n, vector<ll> num) {
    ll kazu = n;
    for (int i = 2; i <= n; i++) {
        while (1) {
            if (kazu % i != 0) break;

            kazu /= i;
            num[i]++;
        }
    }
    if (kazu == n && n != 1)
        num[n]++;
    return num;
    int ans = 0;
    if (kazu != 1) ans++;
    for (int i = 2; i <= sqrt(n); i++) {
        for (int j = 1; j <= num[i]; j++) {
            num[i] -= j;
            ans++;
        }
    }
    return num;
}
const int INF = 1001001001;

//mint�p�̒萔 (10��9�� + 7)
const int mod = 1000000007;

struct mint {
    ll x; // typedef long long ll;
    mint(ll x = 0) :x((x% mod + mod) % mod) {}
    mint operator-() const { return mint(-x); }
    mint& operator+=(const mint a) {
        if ((x += a.x) >= mod) x -= mod;
        return *this;
    }
    mint& operator-=(const mint a) {
        if ((x += mod - a.x) >= mod) x -= mod;
        return *this;
    }
    mint& operator*=(const mint a) { (x *= a.x) %= mod; return *this; }
    mint operator+(const mint a) const { return mint(*this) += a; }
    mint operator-(const mint a) const { return mint(*this) -= a; }
    mint operator*(const mint a) const { return mint(*this) *= a; }
    mint pow(ll t) const {
        if (!t) return 1;
        mint a = pow(t >> 1);
        a *= a;
        if (t & 1) a *= *this;
        return a;
    }

    // for prime mod
    mint inv() const { return pow(mod - 2); }
    mint& operator/=(const mint a) { return *this *= a.inv(); }
    mint operator/(const mint a) const { return mint(*this) /= a; }
};
istream& operator>>(istream & is, const mint & a) { return is >> a.x; }
ostream& operator<<(ostream & os, const mint & a) { return os << a.x; }

/*int main() {
    string s, t;
    cin >> s >> t;
    vector<vector<int> > table('z' + 1, vector<int> (0));
    rep(i, s.size()) {
        table[s[i]].emplace_back(i);
    }
    vector<bool> abc('z' + 1, false);
    rep(i, s.size()) {
        if (s[i] != t[i]) {
            if (abc[s[i]]) {
                cout << "No";
                return 0;
            }
            int mae = s[i];
            s[i] = t[i];
            abc[s[i]] = true;
            table[mae].erase(table[mae].begin());
            vector<bool> abc2(s.size(), false);
            for(int j : table[mae]) {
                if (abc[j]) {
                    cout << "No";
                    return 0;
                }
                s[j] = t[i];
                table[mae].erase(table[mae].begin());
                table[t[i]].emplace_back(j);
                abc2[j] = true;
            }
            for (int j : table[t[i]]) {
                if (i == j) continue;
                if (abc2[j]) continue;
                int mae2 = s[j];
                s[j] = mae;
                if (s[j] != t[j]) {
                    cout << "No";
                    return 0;
                }
                table[mae2].erase(table[mae2].begin());
                table[mae].emplace_back(j);
            }
        }
        else {
            table[s[i]].erase(table[s[i]].begin());
            abc[s[i]] = true;
        }
    }
    cout << "Yes";
    return 0;
}*/
int main() {
    string s, t;
    cin >> s >> t;
    vector<vector<int> > table('z' + 1, vector<int>(0));
    rep(i, s.size()) {
        table[s[i]].emplace_back(t[i]);
    }
    srep(i, 'a', 'z' + 1) {
        sort(table[i].begin(), table[i].end());
        table[i].erase(unique(table[i].begin(), table[i].end()), table[i].end());
    }
    vector<vector<int> > table2('z' + 1, vector<int> (0));
    rep(i, t.size()) {
        table2[t[i]].emplace_back(s[i]);
    }
    srep(i, 'a', 'z' + 1) {
        sort(table2[i].begin(), table2[i].end());
        table2[i].erase(unique(table2[i].begin(), table2[i].end()), table2[i].end());
    }
    srep(i, 'a', 'z' + 1) {
        if (table[i].size() >= 2 || table2[i].size() >= 2) {
            cout << "No" << endl;
            return 0;
        }
    }
    cout << "Yes";
    return 0;
}

Measured memory_bytes: 5848