#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
 
int numberOfConflicts(const std::string* input, const unsigned int& arrayLength);
int main()
{
        unsigned int n = 0;
        std::cin >> n;
        std::string* a;
        a = new std::string [n];
        for(int i = 0; i < n; i++)
        {   
                std::cin >> a[i];
        }   
        std::cout << numberOfConflicts(a, n) << std::endl;
        delete [] a;
        return 0;
}
int numberOfConflicts(const std::string* input, const unsigned int& arrayLength)
{
        unsigned int result = 0;
        std::vector<std::string> duplicates;
        std::vector<std::string>::iterator it; 
        for(int i = 0; i < arrayLength; i++)
        {   
                it = find(duplicates.begin(), duplicates.end(), input[i]);
                for(int j = i + 1; j < arrayLength; j++)
                {   
                        if (input[i] == input[j] && it == duplicates.end())
                        {
                            result++;
                            duplicates.push_back(input[i]);
                            break;
                        }
                }
        }
        return result;
}