rqnoj-165

#include<iostream>#include<cstring>#include<fstream>using namespace std;int b[2222],f[2222],p,i,j,sum,ss;int main(){    string s;    cin>>s;    for(i=s.size()-1;i>=0;--i)    {        if(s[i]=='F')            f[p++]=i;        else if(s[i]=='I')            ss++;        else if(s[i]=='B')            b[i]=ss;    }    for(i=p-1;i>=0;--i)        for(j=s.size()-1;j>f[i];--j)            sum+=b[j];    cout<<sum<<endl;    return 0;}