import sys #input = sys.stdin.readline #input = sys.stdin.buffer.readline #文字列はダメ #sys.setrecursionlimit(1000000) #import bisect #import itertools #import random #from heapq import heapify, heappop, heappush #from collections import defaultdict #from collections import deque #import copy #import math #from functools import lru_cache #@lru_cache(maxsize=None) MOD = pow(10,9) + 7 #MOD = 998244353 #dx = [1,0,-1,0] #dy = [0,1,0,-1] #dx8 = [1,1,0,-1,-1,-1,0,1] #dy8 = [0,1,1,1,0,-1,-1,-1] #和のセグ木にするときは以下の関数を定義する必要あり。 def segfunc(x,y): return x+y class SegmentTree(object): def __init__(self, A, dot, unit): n = 1 << (len(A) - 1).bit_length() tree = [unit] * (2 * n) for i, v in enumerate(A): tree[i + n] = v for i in range(n - 1, 0, -1): tree[i] = dot(tree[i << 1], tree[i << 1 | 1]) self._n = n self._tree = tree self._dot = dot self._unit = unit def __getitem__(self, i): return self._tree[i + self._n] def update(self, i, v): i += self._n self._tree[i] = v while i != 1: i >>= 1 self._tree[i] = self._dot(self._tree[i << 1], self._tree[i << 1 | 1]) def add(self, i, v): self.update(i, self[i] + v) def sum(self, l, r): #これで[l,r)から取り出す。 l += self._n r += self._n l_val = r_val = self._unit while l < r: if l & 1: l_val = self._dot(l_val, self._tree[l]) l += 1 if r & 1: r -= 1 r_val = self._dot(self._tree[r], r_val) l >>= 1 r >>= 1 return self._dot(l_val, r_val) def compress(S): S = set(S); S = list(S) S.sort() dic_comp_ori = {} dic_ori_comp = {} for i,a in enumerate(S): dic_ori_comp[a] = i dic_comp_ori[i] = a return dic_comp_ori, dic_ori_comp def main(): N,K = map(int,input().split()) A = list(map(int,input().split())) dic_comp_ori, dic_ori_comp = compress(A) A = [dic_ori_comp[a] for a in A] MAX = len(dic_comp_ori) s = str(input()) print(A) # dp[k][v]: 今k番目の不等号まで完了して、直前の値がvとなる場合の数 dp = [SegmentTree([0]*MAX,segfunc,0) for _ in range(K+1)] for a in A: # 初期条件 dp[0].add(a,1) for k in range(K): # a未満の和 if s[k] == '<': num = dp[k].sum(0,a) # aより大の和 else: num = dp[k].sum(a+1,MAX) temp = dp[k+1][a] + num temp %= MOD dp[k+1].update(a,temp) ans = dp[K].sum(0,MAX) print(ans%MOD) if __name__ == '__main__': main()