def main():
   
   N = int(input())
   N -= 1
   
   nums = []
   for i in range(1, 10):
   	  for j in range(i+1, 10):
   	  	  nums.append(i * 10 + j)
   
   P = N % 36
   cost = N // 36
   mozi = str(nums[P])
   print(mozi + mozi[-1] * cost)
   
   
if __name__ == '__main__':
    main()