# include<string> # include<iostream> # include<algorithm> # include<vector> # include<set> # include<map> int main( ){ using namespace std; char a[111]; int n,h,s; cin>>h>>s; for(int i=0;i<100;i++){ cin>>a[i]; if(a[i]=='u'&&s!=0){ s-=1; }if(a[i]=='d'&&s!=h){ s+=1; } }cout<<s<<endl; return 0; }