import heapq

n = int(input())

# Generate all valid (a, b) pairs where a < b
pairs = []
for a in range(1, 10):
    for b in range(a + 1, 10):
        pairs.append((a, b))

# Initialize the heap with the initial length of 2 for each pair
heap = []
for a, b in pairs:
    heapq.heappush(heap, (2, a, b))

# Process the first (n-1) elements
for _ in range(n - 1):
    length, a, b = heapq.heappop(heap)
    heapq.heappush(heap, (length + 1, a, b))

# The nth element is now the smallest in the heap
length, a, b = heapq.heappop(heap)

# Generate the resulting number as a string
result = str(a) + str(b) + (length - 2) * str(b)
print(result)