A sequence $A=[1, 2, \cdots, N]$ of length $N$ is given. We want to remove the minimum number of elements from $A$ such that when the remaining elements are treated as strings and concatenated in order, the resulting string does not contain 67 as a substring.

For example, if we remove the elements $2$ and $4$ from $[1,2,3,4,5,6,7]$, the sequence becomes $[1,3,5,6,7]$, and the string $13567$ formed by concatenating them contains $67$ as a substring, which does not satisfy the condition.

Find the minimum number of elements to remove so that the remaining sequence satisfies the given condition.

The input is given in the following format.

$N$

Print the minimum number of elements to remove.

• $1 \leq N \leq 10^{18}$.