#include <bits/stdc++.h>

using namespace std;


int main(){
    ios::sync_with_stdio(0);
    cin.tie(0);

    string s;
    cin >> s;

    set<char> seen;
    bool lower = false, upper = false;

    for(char c : s){
        if(isupper(c)){
            upper = true;
        }
        else if(islower(c)){
            lower = true;
        }

        if(seen.count(c)){
            cout << "No" << endl;
            return 0;
        }
        seen.insert(c);
    }

    if(lower && upper){
        cout << "Yes" << endl;
    } else{
        cout << "No" << endl;
    }

    cout << flush;

    return 0;
}