import sys

K = int(input())

NLUNLUN = [[-1 for _ in range(11)] for _ in range(10)]
def num_lunlun(n, digit):
    if digit == 1:
        NLUNLUN[n][digit] = 1
        return NLUNLUN[n][digit]

    if digit == 2:
        if 0 < n < 9:
            NLUNLUN[n][digit] = 3
        else:
            NLUNLUN[n][digit] = 2
        return NLUNLUN[n][digit]

    n2 = 0
    if n - 1 >= 0:
        n2 += NLUNLUN[n-1][digit-1]
    n2 += NLUNLUN[n][digit-1]
    if n + 1 <= 9:
        n2 += NLUNLUN[n+1][digit-1]
    NLUNLUN[n][digit] = n2
    return NLUNLUN[n][digit]


if K < 10:
    print(K)
    sys.exit(0)

k = 0
for digit in range(1, 11):
    for n in range(10):
        tmp = num_lunlun(n, digit)
        if n > 0:
            if k + tmp >= K:
                ans = str(n)
                n2 = n
                for digit2 in range(digit-1, 1, -1):
                    if n2 - 1 >= 0:
                        tmp = NLUNLUN[n2 - 1][digit2]
                        if k + tmp >= K:
                            ans += str(n2 - 1)
                            n2 -= 1
                            continue
                        k += tmp

                    tmp = NLUNLUN[n2][digit2]
                    if k + tmp >= K:
                        ans += str(n2)
                        continue
                    k += tmp

                    if n2 + 1 <= 9:
                        tmp = NLUNLUN[n2 + 1][digit2]
                        if k + tmp >= K:
                            ans += str(n2 + 1)
                            n2 += 1
                            continue
                        k += tmp

                ans = int(ans + str(n2 + K - k - 2))
                print(ans)

                sys.exit(0)
            k += tmp


### FIXED CODE ###

import sys

K = int(input())

NLUNLUN = [[-1 for _ in range(11)] for _ in range(10)]
def num_lunlun(n, digit):
    if digit == 1:
        NLUNLUN[n][digit] = 1
        return NLUNLUN[n][digit]

    if digit == 2:
        if 0 < n < 9:
            NLUNLUN[n][digit] = 3
        else:
            NLUNLUN[n][digit] = 2
        return NLUNLUN[n][digit]

    n2 = 0
    if n - 1 >= 0:
        n2 += NLUNLUN[n-1][digit-1]
    n2 += NLUNLUN[n][digit-1]
    if n + 1 <= 9:
        n2 += NLUNLUN[n+1][digit-1]
    NLUNLUN[n][digit] = n2
    return NLUNLUN[n][digit]


if K < 10:
    print(K)
    sys.exit(0)

k = 0
for digit in range(1, 11):
    for n in range(10):
        tmp = num_lunlun(n, digit)
        if n > 0:
            if k + tmp >= K:
                ans = str(n)
                n2 = n
                for digit2 in range(digit-1, 1, -1):
                    if n2 - 1 >= 0:
                        tmp = NLUNLUN[n2 - 1][digit2]
                        if k + tmp >= K:
                            ans += str(n2 - 1)
                            n2 -= 1
                            continue
                        k += tmp

                    tmp = NLUNLUN[n2][digit2]
                    if k + tmp >= K:
                        ans += str(n2)
                        continue
                    k += tmp

                    if n2 + 1 <= 9:
                        tmp = NLUNLUN[n2 + 1][digit2]
                        if k + tmp >= K:
                            ans += str(n2 + 1)
                            n2 += 1
                            continue
                        k += tmp

                if ans[-1] == '0':
                    ans = int(ans + str(n2 + K - k - 1))
                else:
                    ans = int(ans + str(n2 + K - k - 2))
                print(ans)

                sys.exit(0)
            k += tmp