
#include <cstdio>
#include <cstring>
#include <iostream>
#include <stdio.h>
#include <iomanip>
#include <string>
using namespace std;
int main()
{
int h,s;
cin >> h >> s;
string co;
cin >> co;
int cur = s;
for(int i = 0;i<co.length();i++)
{
if(co[i] == 'u')
{
cur -= 1;
}
if(co[i] == 'd')
{
cur += 1;
}
if(cur <= 0)
{
cur = 0;
}
else if(cur >= h)
{
cur = h;
}
}
cout << cur;
return 0;
}
#include <iostream>
using namespace std;
int main(){
int h,s;
string str;
cin>>h>>s>>str;
for(int i=0;i<str.size();i++){
if(str[i]=='u'){
if(s>0){
s--;
}
}else{
if(s<h){
s++;
}
}
}
cout<<s;
}