#include <stdio.h>
#include <string.h>

int main() {
    int N;
    scanf("%d", &N);
    
    char strings[N][101]; // Array to store the strings
    for (int i = 0; i < N; i++) {
        scanf("%s", strings[i]);
    }

    int count = 0; // Variable to count the number of distinct concatenated strings

    // Iterate over each pair of strings and check if the concatenated string is distinct
    for (int i = 0; i < N; i++) {
        for (int j = 0; j < N; j++) {
            if (i != j) {
                char concatenated[201]; // Array to store the concatenated string
                strcpy(concatenated, strings[i]);
                strcat(concatenated, strings[j]);

                // Check if the concatenated string is distinct from all previously formed strings
                int distinct = 1;
                for (int k = 0; k < N; k++) {
                    if (k != i && k != j && strcmp(concatenated, strings[k]) == 0) {
                        distinct = 0;
                        break;
                    }
                }

                // If the concatenated string is distinct, increment the count
                if (distinct) {
                    count++;
                }
            }
        }
    }

    printf("%d\n", count);

    return 0;
}