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29. Coin Combinations I

Volume problems

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• 05. Trailing Zeros
• 17. Number Spiral
• 23. Apple Division
• 25. Josephus Queries
• 26. Exponentiation
• 29. Coin Combinations I

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Time limit 4000/4000/4000/4000 ms. Memory limit 65000/65000/65000/65000 Kb. Difficulty Beta

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:
  • 2+2+5
  • 2+5+2
  • 5+2+2
  • 3+3+3
  • 2+2+2+3
  • 2+2+3+2
  • 2+3+2+2
  • 3+2+2+2

Input
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 c1,c2,…,cn : the value of each coin.

Output
Print one integer: the number of ways modulo 109+7 .

Constraints
  • 1≤n≤100
  • 1≤x≤106
  • 1≤c(i)≤106

Example
Input:
3 9
2 3 5
Output:
8

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