#include <cstdlib>
#include <cstdio>
#include <cstring>
#include <string>
using namespace std;
const int MAXN=3000;
int Num[MAXN],F[MAXN]={0},N,ans=0;
char str[MAXN];
int main()
{
	freopen("fbi.in","r",stdin);
	freopen("fbi.out","w",stdout);
	gets(str); N=strlen(str);
	for(int i=1;i<=N;i++)
	{
		switch(str[i-1])
		{
		case 'F':Num[i]=1;break;
		case 'B':Num[i]=2;break;
		case 'I':Num[i]=3;break;
		default:Num[i]=0;break;
		}
	}
	for(int i=1;i<=N;i++)
	{
		F[i]=0;
		if(Num[i]==0) continue;
		if(Num[i]==1) {F[i]=1;continue;}
		for(int j=1;j<=N-1;j++)
			if(Num[j]==Num[i]-1) F[i]+=F[j];
		if(Num[i]==3) ans+=F[i];
	}
	printf("%d\n",ans);
	return 0;
}