S_N3

#include <iostream>
#include <cmath>
#include <vector>
#include <queue>
#include <algorithm>
#include <string>
#include <stack>
#include <set>
#include <map>
#define pii pair <int, int>
#define pb(x) push_back(x)
using namespace std;
using ll = long long;
using ld = long double;
using db = double;
void cv(vector <int> &v) {
    for (auto x : v) cout << x << ' ';
    cout << "\n";
}

void cvl(vector <ll> &v) {
    for (auto x : v) cout << x << ' ';
    cout << "\n";
}


void cvv(vector <vector <int> > &v) {
    for (auto x : v) cv(x);
    cout << "\n";
}

void cvb(vector <bool> v) {
    for (bool x : v) cout << x << ' ';
    cout << "\n";
}

void cvs(vector <string>  v) {
    for (auto a : v) {
        cout << a << "\n";
    }
}

void cvp(vector <pii> a) {
    for (auto p : a) {
        cout << p.first << ' ' << p.second << "\n";
    }
    cout << "\n";
}

#include <fstream>

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    string s;
    ifstream file("sum24.txt");
    //ifstream file("test.txt");
    getline(file, s);
    //cout << s;
    int n = s.size();
    int i = 0;
    int fr=-1, to=-1;
    int ans = 0;
    for (int i = 0; i < n; ++i) {
        int E = 0;
        if (fr == -1) {
            while (i < n && s[i] == 'A') {
                i++;
            }
            fr = i;
        }
        while (i < n && s[i] != 'A') {
            if (s[i] == 'E') {
                E++;
            }
            i++;
        }
        if (E >= 3) {
            to = i - 1;
            int l = to - fr + 1;
            ans = max(ans, l);
        }
        fr=-1;
        to=-1;
    }
    cout << ans;
}