#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef string str;
int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    str s;
    cin >> s;
    if ((s[0] == s[1] && s[1] != s[2]) || (s[1] == s[2] && s[2] != s[0]) || (s[0] == s[2] && s[2] != s[1])) cout << "Yes\n";
    else cout << "No\n";
    return 0;
}