#include<bits/stdc++.h> using namespace std; int n,s,k=1; int main(){ char a[10005]; cin>>n; for(int i=1;i<=n;i++){ cin>>a[i]; if(a[i]=='V'){ s++; if(a[i]==a[i-1]) k++; else{ if(k>=3) s=s+k-2; k=1; } if(i==n&&k>=3) s=s+k-2; } else if(a[i]=='T') continue; else s--; } cout<<s; return 0; }