N = int(input())
if N == 1:
    for i0 in range(1):
        print(chr(i0+97), sep='')
if N == 2:
    for i0 in range(1):
        for i1 in range(i0 + 2):
            print(chr(i0+97), chr(i1+97), sep='')
if N == 3:
    for i0 in range(1):
        for i1 in range(i0 + 2):
            for i2 in range(max(i0, i1) + 2):
                print(chr(i0+97), chr(i1+97), chr(i2+97), sep='')
if N == 4:
    for i0 in range(1):
        for i1 in range(i0 + 2):
            for i2 in range(max(i0, i1) + 2):
                for i3 in range(max(i0, i1, i2) + 2):
                    print(chr(i0+97), chr(i1+97), chr(i2+97), chr(i3+97), sep='')
if N == 5:
    for i0 in range(1):
        for i1 in range(i0 + 2):
            for i2 in range(max(i0, i1) + 2):
                for i3 in range(max(i0, i1, i2) + 2):
                    for i4 in range(max(i0, i1, i2, i3) + 2):
                        print(chr(i0+97), chr(i1+97), chr(i2+97), chr(i3+97), chr(i4+97), sep='')
if N == 6:
    for i0 in range(1):
        for i1 in range(i0 + 2):
            for i2 in range(max(i0, i1) + 2):
                for i3 in range(max(i0, i1, i2) + 2):
                    for i4 in range(max(i0, i1, i2, i3) + 2):
                        for i5 in range(max(i0, i1, i2, i3, i4) + 2):
                            print(chr(i0+97), chr(i1+97), chr(i2+97), chr(i3+97), chr(i4+97), chr(i5+97), sep='')
if N == 7:
    for i0 in range(1):
        for i1 in range(i0 + 2):
            for i2 in range(max(i0, i1) + 2):
                for i3 in range(max(i0, i1, i2) + 2):
                    for i4 in range(max(i0, i1, i2, i3) + 2):
                        for i5 in range(max(i0, i1, i2, i3, i4) + 2):
                            for i6 in range(max(i0, i1, i2, i3, i4, i5) + 2):
                                print(chr(i0+97), chr(i1+97), chr(i2+97), chr(i3+97), chr(i4+97), chr(i5+97), chr(i6+97), sep='')
if N == 8:
    for i0 in range(1):
        for i1 in range(i0 + 2):
            for i2 in range(max(i0, i1) + 2):
                for i3 in range(max(i0, i1, i2) + 2):
                    for i4 in range(max(i0, i1, i2, i3) + 2):
                        for i5 in range(max(i0, i1, i2, i3, i4) + 2):
                            for i6 in range(max(i0, i1, i2, i3, i4, i5) + 2):
                                for i7 in range(max(i0, i1, i2, i3, i4, i5, i6) + 2):
                                    print(chr(i0+97), chr(i1+97), chr(i2+97), chr(i3+97), chr(i4+97), chr(i5+97), chr(i6+97), chr(i7+97), sep='')
if N == 9:
    for i0 in range(1):
        for i1 in range(i0 + 2):
            for i2 in range(max(i0, i1) + 2):
                for i3 in range(max(i0, i1, i2) + 2):
                    for i4 in range(max(i0, i1, i2, i3) + 2):
                        for i5 in range(max(i0, i1, i2, i3, i4) + 2):
                            for i6 in range(max(i0, i1, i2, i3, i4, i5) + 2):
                                for i7 in range(max(i0, i1, i2, i3, i4, i5, i6) + 2):
                                    for i8 in range(max(i0, i1, i2, i3, i4, i5, i6, i7) + 2):
                                        print(chr(i0+97), chr(i1+97), chr(i2+97), chr(i3+97), chr(i4+97), chr(i5+97), chr(i6+97), chr(i7+97), chr(i8+97), sep='')
if N == 10:
    for i0 in range(1):
        for i1 in range(i0 + 2):
            for i2 in range(max(i0, i1) + 2):
                for i3 in range(max(i0, i1, i2) + 2):
                    for i4 in range(max(i0, i1, i2, i3) + 2):
                        for i5 in range(max(i0, i1, i2, i3, i4) + 2):
                            for i6 in range(max(i0, i1, i2, i3, i4, i5) + 2):
                                for i7 in range(max(i0, i1, i2, i3, i4, i5, i6) + 2):
                                    for i8 in range(max(i0, i1, i2, i3, i4, i5, i6, i7) + 2):
                                        for i9 in range(max(i0, i1, i2, i3, i4, i5, i6, i7, i8) + 2):
                                            print(chr(i0+97), chr(i1+97), chr(i2+97), chr(i3+97), chr(i4+97), chr(i5+97), chr(i6+97), chr(i7+97), chr(i8+97), chr(i9+97), sep='')

Measured memory_bytes: 5776