#include <fstream>
#include <algorithm>
#include <string>
#include <cstring>

using namespace std;

ifstream fin("fbi.in");
ofstream fout("fbi.out");

string str;
int kountf, kountb, kounti, kounto;

void Init() {
	//Pill.
	return ;
}
void Out() {
	fout<<kountf<<kountb<<kounti<<kounto<<endl;
	return ;
}
void Work() {
	kountf = kountb = kounti = kounto = 0;
	
	fin>>str;
	for(int i=0;i<str.length();i++)
	{
		if(str[i]=='F')
			kountf++;
		else if(str[i]=='B')
			kountb += kountf;
		else if(str[i]=='I')
			kounti += kountb;
		else
			kounto++;//Pill.
	}
	
	//Out();
	
	fout<<kounti<<endl;
	return ;
}
int main() {
	
	Init();
	
	Work();
	
	fin.close();
	fout.close();
	
	return 0;
}