#include <bits/stdc++.h>
using namespace std;

using ll = long long;
#define rep(i, n) for (int i = 0; i < n; i++)
#define INF (1LL << 60)
#define all(v) (v).begin(), (v).end()

template <class T>
void chmin(T &a, T b) {
    if (a > b) a = b;
}

template <class T>
void chmax(T &a, T b) {
    if (a < b) a = b;
}

struct ArbitraryModInt {
    int x;

    ArbitraryModInt() : x(0) {}

    ArbitraryModInt(int64_t y)
        : x(y >= 0 ? y % mod() : (mod() - (-y) % mod()) % mod()) {}

    static int &mod() {
        static int mod = 0;
        return mod;
    }

    static int set_mod(int md) { mod() = md; }

    ArbitraryModInt &operator+=(const ArbitraryModInt &p) {
        if ((x += p.x) >= mod()) x -= mod();
        return *this;
    }

    ArbitraryModInt &operator-=(const ArbitraryModInt &p) {
        if ((x += mod() - p.x) >= mod()) x -= mod();
        return *this;
    }

    ArbitraryModInt &operator*=(const ArbitraryModInt &p) {
        unsigned long long a = (unsigned long long)x * p.x;
        unsigned xh = (unsigned)(a >> 32), xl = (unsigned)a, d, m;
        asm("divl %4; \n\t" : "=a"(d), "=d"(m) : "d"(xh), "a"(xl), "r"(mod()));
        x = m;
        return *this;
    }

    ArbitraryModInt &operator/=(const ArbitraryModInt &p) {
        *this *= p.inverse();
        return *this;
    }

    ArbitraryModInt operator-() const { return ArbitraryModInt(-x); }

    ArbitraryModInt operator+(const ArbitraryModInt &p) const {
        return ArbitraryModInt(*this) += p;
    }

    ArbitraryModInt operator-(const ArbitraryModInt &p) const {
        return ArbitraryModInt(*this) -= p;
    }

    ArbitraryModInt operator*(const ArbitraryModInt &p) const {
        return ArbitraryModInt(*this) *= p;
    }

    ArbitraryModInt operator/(const ArbitraryModInt &p) const {
        return ArbitraryModInt(*this) /= p;
    }

    bool operator==(const ArbitraryModInt &p) const { return x == p.x; }

    bool operator!=(const ArbitraryModInt &p) const { return x != p.x; }

    ArbitraryModInt inverse() const {
        int a = x, b = mod(), u = 1, v = 0, t;
        while (b > 0) {
            t = a / b;
            swap(a -= t * b, b);
            swap(u -= t * v, v);
        }
        return ArbitraryModInt(u);
    }

    ArbitraryModInt pow(int64_t n) const {
        ArbitraryModInt ret(1), mul(x);
        while (n > 0) {
            if (n & 1) ret *= mul;
            mul *= mul;
            n >>= 1;
        }
        return ret;
    }

    friend ostream &operator<<(ostream &os, const ArbitraryModInt &p) {
        return os << p.x;
    }

    friend istream &operator>>(istream &is, ArbitraryModInt &a) {
        int64_t t;
        is >> t;
        a = ArbitraryModInt(t);
        return (is);
    }
};

int main() {
    string S;
    cin >> S;
    if (S[0] == S[1] && S[0] != S[2])
        cout << "Yes" << endl;
    else
        cout << "No" << endl;
}