CF367E Sereja and Intervals

Sereja is interested in intervals of numbers, so he has prepared a problem about intervals for you. An interval of numbers is a pair of integers $ [l,r] $ $ (1

The first line contains integers $ n $ , $ m $ , $ x $ $ (1

In a single line print the answer modulo $ 1000000007 $ $ (10^{9}+7) $ .

In third example next sequences will be correct: $ {[1,1],[3,3]} $ , $ {[1,2],[3,3]} $ , $ {[2,2],[3,3]} $ , $ {[3,3],[1,1]} $ , $ {[3,3],[2,2]} $ , $ {[3,3],[1,2]} $ .