X = int(input())
ans = 0
x = 0
dx = [2, -1]
for _ in range(100):
    x += dx[0]
    ans += 2
    if X == x:
        break
    x += dx[0]
    ans += 2
    if X == x:
        break
    x += dx[1]
    ans += 1
    if X == x:
        break
    x += dx[1]
    ans += 1
    if X == x:
        break
    x += dx[0]
    ans += 2
    if X == x:
        break
    x += dx[1]
    ans += 1
    if X == x:
        break
    x += dx[1]
    ans += 1
    if X == x:
        break

print(ans)