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main()
{
    int c,n;
    while(c!=3)
    {
        printf("\nChon 1: Nhap so nguyen duong");
        printf("\nChon 2: In duong cheo chinh");
        printf("\nChon 3: Thoat");
        printf("\nMoi ban chon: ");
        scanf("%d",&c);
        switch(c)
        {
            case 1:
                Nhapmatran(&n,A);
                break;
            case 2:
                Induongcheo(n,A);
                break;
            default:
                printf("Khong hop le");
                system("pause");
                system("cls");
        }
    }
}