Consider a money system consisting of $n$ coins. Each coin has a positive integer value. Your task is to calculate the number of distinct ways you can produce a money sum $x$ using the available coins.
For example, if the coins are ${2,3,5}$ and the desired sum is $9$ , there are $8$ ways:
The first input line has two integers $n$ and $x$ : the number of coins and the desired sum of money.
The second line has $n$ distinct integers $c_1,c_2,\dots,c_n$ : the value of each coin.
Print one integer: the number of ways modulo $10^9+7$ .