#include<iostream>using namespace std;int main(){ int num; char *a; int s,f,c,flag; while(cin>>num) { flag=0; s=f=c=0; a= new char[num]; for(int i=0;i<num;i++) {cin>>a[num];if(a[num]=='S')s++;else if(a[num]=='F')f++;else if(a[num]=='C')c++; } if(s==num||f==num||c==num)flag=num; else if(s!=0&&f!=0&&c!=0)flag=num; else {if(s==0)flag=f;else if(f==0)flag=c;else if(c==0)flag=s; } cout<<flag<<endl; }}
