#include <iostream> #include <vector> #include <cmath> #include <map> #include <set> #include <iomanip> #include <queue> #include <algorithm> #include <numeric> #include <deque> #include <complex> #include <cassert> using namespace std; using ll = long long; const int modc = 1000000007; class mint { long long x; public: mint(long long x=0) : x((x%modc+modc)%modc) {} mint operator-() const { return mint(-x); } mint& operator+=(const mint& a) { if ((x += a.x) >= modc) x -= modc; return *this; } mint& operator-=(const mint& a) { if ((x += modc-a.x) >= modc) x -= modc; return *this; } mint& operator*=(const mint& a) { (x *= a.x) %= modc; return *this; } mint operator+(const mint& a) const { mint res(*this); return res+=a; } mint operator-(const mint& a) const { mint res(*this); return res-=a; } mint operator*(const mint& a) const { mint res(*this); return res*=a; } mint pow(ll t) const { if (!t) return 1; mint a = pow(t>>1); a *= a; if (t&1) a *= *this; return a; } // for prime mod mint inv() const { return pow(modc-2); } mint& operator/=(const mint& a) { return (*this) *= a.inv(); } mint operator/(const mint& a) const { mint res(*this); return res/=a; } friend ostream& operator<<(ostream& os, const mint& m){ os << m.x; return os; } }; template<class T> struct BIT { vector<T> bit; long long N; BIT (long long n){ N = n; bit.resize(N); } void add(long long loc, T val){ loc++; while(loc <= N){ bit[loc-1] += val; loc += loc & -loc; } } T sum(long long l, long long r){ T res = _sum(r) - _sum(l-1); return res; } T _sum(long long r){ r++; T res = 0; while(r > 0){ res += bit[r-1]; r -= r & -r; } return res; } }; template <typename T> void compress(vector<T> &A){ map<T, T> comp; int N = A.size(), i=0; for (int i=0; i<N; i++) comp[A[i]]; for (auto &e : comp){ e.second = i; i++; } for (int i=0; i<N; i++) A[i] = comp[A[i]]; } int main(){ ll N, K; string S; cin >> N >> K; vector<ll> A(N); for (int i=0; i<N; i++) cin >> A[i]; cin >> S; compress(A); vector<BIT<mint>> dp(K+1, BIT<mint>(N)); for (int i=0; i<N; i++){ for (int j=1; j<=K; j++){ if (S[j-1] == '<') dp[j].add(A[i], dp[j-1].sum(0, A[i]-1)); else dp[j].add(A[i], dp[j-1].sum(A[i]+1, N-1)); } dp[0].add(A[i], 1); } cout << dp[K].sum(0, N-1) << endl; return 0; }