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

int main() {
    FILE *fin = fopen("cifra.in", "r");
    FILE *fout = fopen("cifra.out", "w");

    if (fin == NULL || fout == NULL) {
        printf("Eroare la deschiderea fișierelor!\n");
        return 1;
    }

    int T;
    fscanf(fin, "%d", &T);

    char N[110]; 
    int suma = 0;

    for (int i = 0; i < T; i++) {
        fscanf(fin, "%s", N);

        int ultima_cifra = N[strlen(N) - 1] - '0';
        int patrat = (ultima_cifra * ultima_cifra) % 10; 
        suma = (suma + patrat) % 10; 

        fprintf(fout, "%d\n", suma);
    }

    fclose(fin);
    fclose(fout);
    return 0;
}