#include <stdio.h>

int main(void) {
    int month;

    printf("Input month: ");
    scanf("%d", &month);

    switch (month) {
        case 12:
        case 1:
        case 2:
            puts("It is winter.");
            break;
        case 3:
        case 4:
        case 5:
            puts("It is spring.");
            break;
        case 6:
        case 7:
        case 8:
            puts("It is summer.");
            break;
        case 9:
        case 10:
        case 11:
            puts("It is autumn.");
            break;
        default:
            puts("Unknown month.");
    }

    return 0;
}