#!/usr/bin/env python3
from collections import defaultdict


def read_ints() -> list[int]:
    return [int(x) for x in input().split()]


def main():
    _ball_count, height = read_ints()
    balls = read_ints()

    counts = defaultdict(lambda: 0)

    for size in balls:
        counts[size] += 1

    counts = list(counts.values())

    dp = [[1] * (len(counts) + 1)]

    for _ in range(height):
        dp.append([0])

        for i, count in enumerate(counts):
            value = dp[-1][i] + dp[-2][i] * count
            value %= 1_000_000_007
            dp[-1].append(value)

    print(dp[-1][-1])


main()