For a provided integer \(k\), find the maximum value of \(m+n\), where \(1 \leqslant m,n \leqslant k\) and \((n^2 - nm - m^2)^{2} = 1\).

Note: The answer can exceed the range of a 32-bit integer.

Input format

The only line of the input contains one integer \(k\).

Output format

Print the maximum value of \(m+n\), where \(1 \leqslant m,n \leqslant k\) and \((n^2 - nm - m^2)^{2} = 1\).

Constraints

\(1 \leqslant k \leqslant 10^{18}\)