n, k = map(int, input().split())
A = list(map(int, input().split()))
S = list(input())
mod = 10**9 + 7

DP = [[0 for _ in range(k + 1)] for _ in range(n)]
for i in range(n - 1):
    DP[i][0] += 1
    for j in range(min(k, i + 1)):
        for l in range(i + 1, n):
            if S[j] == '<':
                if A[i] < A[l]:
                    DP[l][j + 1] += DP[i][j]
                    DP[l][j + 1] %= mod
            elif S[j] == '>':
                if A[i] > A[l]:
                    DP[l][j + 1] += DP[i][j]
                    DP[l][j + 1] %= mod
ans = 0
for i in range(n):
    ans += DP[i][k]
    ans %= mod
print(ans)