#include<iostream> using namespace std; int main(){ int h,s; string s1; cin>>h>>s>>s1; int sa=s1.size(); for(int i=0;i<sa;i++){ if(s1[i]=='u'&&s>0){ s--; }else if(s1[i]=='d'&&s<h){ s++; } } cout<<s; return 0; }