Problems
Side of the square
Side of the square
Find the integer length of the square, which can be obtained from the two rectangles \textbf{a x b} and \textbf{c x d}, cut them into rectangles and then folded so as to obtain the greatest possible area of the square.
\InputFile
In one row there are four real numbers \textbf{a}, \textbf{b}, \textbf{c}, \textbf{d}. The area of each rectangle is less than \textbf{2}·\textbf{10^9}.
\OutputFile
Derive a single number - the educated side of the square.
Input example #1
1 2 3 4
Output example #1
3