#include <stdio.h>
#include <stdlib.h>

void sort(int *x, int *n);

int main(void) {
    int N;
    int abc[300] = {0};
    int it = 0;
    int pu = 0;
    scanf("%d", &N);
    for (int i = 0; i < N*3; i++) {
        scanf("%d", &abc[i]);
    }
    sort(abc, &N);

    for (int i = 1; i < N*3+1; i++) {
        it++;
        if (abc[i-1] != abc[i]) {
            pu += it / 2;
            it = 0;
        }
    }
    pu += (N*3-pu*2) / 4;
    printf("%d\n", pu);

    return EXIT_SUCCESS;
}

void sort(int *x, int *n) {
    int t;
    for (int i = (*n)*3; i > 1; i--) {
        for (int j = 1; j < i; j++) {
            if (*(x+j-1) > *(x+j)) {
                t = *(x+j-1);
                *(x+j-1) = *(x+j);
                *(x+j) = t;
            }
        }
    }
    return;
}