Problems
Parallelogram
Parallelogram
Given four numbers $a, b, c, d$, defining lengths of pieces. Find out, if it is possible to form a parallelogram from these pieces.
\InputFile
Four real numbers $a, b, c, d$.
\OutputFile
Print a word \textbf{"YES"} if it is possible to form a parallelogram or \textbf{"NO"} otherwise.
Input example #1
2 4 2 4
Output example #1
YES