Untitled

#include <iostream>
#include <string>
using namespace std;

int main() {
	setlocale(LC_ALL, "Russian");
	string a; 
	int counter = 0;
	cin >> a;

	for (int i = 0; i < a.length(); i++) {
		if (a[i] == 'a') {
			counter++;
		}
	}
	cout << counter;

}