def find_magic_number(k):
    count =0
    num= 0
    
    while count < k:
        num+=1 
        if num&7==0 or num%10==7:
            count+=1 
    return num
if __name__=='__main__':
    k = int(input().strip())
    result = fint_magic_number(k)
   print(result) 
   