d = {}
def get(n,i):
    if n < 0: return 0
    if n == 0: return i==0
    if (n,i) in d: return d[n,i]
    v = get((n-3)//10,i) + get((n-5)//10,(i-1)%3) + (i==0)
    d[n,i] = v
    return v

N = int(input())
ng = 554
ok = 5533533555333355355553556
while ok-ng > 1:
    mid = (ok+ng)//2
    if get((mid-5)//10,2) >= N: ok = mid
    else: ng = mid
print(ok)