#include<bits/stdc++.h>
using namespace std;
int main(int argc, char const *argv[]) {
  int n,counter=0;
  bool array1[4];
  memset(array1,false,sizeof(array1));
  cin>>n;
  string s;
  cin>>s;
  for(int i=0;i<n;++i)
  {
    if(s.at(i)>='0'&&s.at(i)<='9')
    {
      array1[0]=true;
    }
    if(s.at(i)>='a'&&s.at(i)<='z')
    {
      array1[1]=true;
    }
    if(s.at(i)>='A'&&s.at(i)<='Z')
    {
      array1[2]=true;
    }
    if(s.at(i)=='!'||s.at(i)=='@'||s.at(i)=='#'||s.at(i)=='$'||s.at(i)=='%'||s.at(i)=='^'||s.at(i)=='&'||s.at(i)=='*'||s.at(i)=='('||s.at(i)==')'||s.at(i)=='-'||s.at(i)=='+')
    {
      array1[3]=true;
    }
  }
    for(int i=0;i<4;++i)
    {
      if(array1[i])
      {
        counter++;
      }
    }
    int ans=4-counter;
  if(n<=5&&n+ans<=5)
    {
      while(n+ans<=5)
      {
        ans++;
      }
      cout<<ans;
    }
    else{
      cout<<ans;
    }

  return 0;
}