#include<stdio.h>
 
int main(void){
  int n;
  scanf("%d",&n);
  
  char s[n][11];
  for(int i = 0;i < n;i++)
    scanf("%s",&s[i]);
  
  int count = 0;
  char check[n][11];
  for(int i = 0;i < n;i++){
    int flag = 1;
    int j = 0;
    while(check[j] != NULL || flag){
      if(check[j] == s[i])
        flag = 0;
      j++;
    }
    if(flag){
      while(check[j] != NULL)
        j++;
      check[j] = s[i];
      count = j;
    }
  }
  printf("%d",count);
      
  return 0;
}