#include<iostream> #include<cstring> using namespace std; char command[101]; int h,s; int main() { cin>>s>>h; cin>>command; for(int i=0;i<strlen(command);i++){ if(command[i]=='u'){ if(s>0){ s--; } } else if(command[i]=='d'&&s<h){ s++; } } cout<<s; return 0; }