#include<bits/stdc++.h>
using namespace std;
char f[2050];
string tem;
int i=1,j;
long long ans=0,l,a[2050],t;
int main()
{
	freopen("fbi.in","r",stdin);
	freopen("fbi.out","w",stdout);
//	cin>>tem;
	//int i=1;
	//t=sizeof(tem);
	//for(i=1;i<=t+1;i++);
	scanf("%s",f+1);
	while(f[i])
	i++;
	l=i-1;
	for(i=l;i;i--)
	{
		a[i]=a[i+1];
		if(f[i]=='I')a[i]++;
	}
	for(i=1;i<=l;i++)
	if(f[i]=='F')
	for(j=i;j<=l;j++)
	if(f[j]=='B')
	ans+=a[j];
	cout<<ans;
	return 0;
}