Letras

#include<iostream>
#include<string.h>
#include<map>
using namespace std;

string s;
map<char, map<int, bool>> viz;
map<char, map<int, int>> dp;

int solve(char last, int i){
    if(i >= s.size()) return 0;
    if(viz[last][i]) return dp[last][i];
    int L = 0;
    if(last <= s[i]) L = 1 + solve(s[i], i+1);
    int R = solve(last, i+1);
    viz[last][i] = true;
    return dp[last][i] = max(L, R);
}



int main(){
    cin >> s;
    cout << solve('A',0) << endl;
}