#include<cstdio>
#include<algorithm>
#include<string>
#include<cstring>
using namespace std;
char ch[3000],p[3]={'I','B','F'};
int s[4][3000]={0};
int main(){
	freopen("fbi.in","r",stdin);
	freopen("fbi.out","w",stdout);
	scanf("%s",ch);
	for (int i=0;i<=strlen(ch);i++) s[0][i]=1;
	for (int i=1;i<=3;i++){
		for (int j=strlen(ch)-1;j>=0;j--){
			if (ch[j]==p[i-1]) s[i][j]=s[i][j+1]+s[i-1][j+1];
			else s[i][j]=s[i][j+1];
			//printf("%d ",s[i][j]);
		}
		//printf("\n");
	}
	printf("%d",s[3][0]);
	return 0;
}