#line 1 "main.cpp" #pragma region Macros #include using namespace std; template inline bool chmax(T &a, T b) { if(a < b) { a = b; return 1; } return 0; } template inline bool chmin(T &a, T b) { if(a > b) { a = b; return 1; } return 0; } #ifdef DEBUG template ostream &operator<<(ostream &os, const pair &p) { os << '(' << p.first << ',' << p.second << ')'; return os; } template ostream &operator<<(ostream &os, const vector &v) { os << '{'; for(int i = 0; i < (int)v.size(); i++) { if(i) { os << ','; } os << v[i]; } os << '}'; return os; } void debugg() { cerr << endl; } template void debugg(const T &x, const Args &... args) { cerr << " " << x; debugg(args...); } #define debug(...) \ cerr << __LINE__ << " [" << #__VA_ARGS__ << "]: ", debugg(__VA_ARGS__) #define dump(x) cerr << __LINE__ << " " << #x << " = " << (x) << endl #else #define debug(...) (void(0)) #define dump(x) (void(0)) #endif struct Setup { Setup() { cin.tie(0); ios::sync_with_stdio(false); cout << fixed << setprecision(15); } } __Setup; using ll = long long; #define OVERLOAD3(_1, _2, _3, name, ...) name #define ALL(v) (v).begin(), (v).end() #define RALL(v) (v).rbegin(), (v).rend() #define REP1(i, n) for(int i = 0; i < int(n); i++) #define REP2(i, a, b) for(int i = (a); i < int(b); i++) #define REP(...) OVERLOAD3(__VA_ARGS__, REP2, REP1)(__VA_ARGS__) #define UNIQUE(v) sort(ALL(v)), (v).erase(unique(ALL(v)), (v).end()) #define SZ(v) ((int)(v).size()) const int INF = 1 << 30; const ll LLINF = 1LL << 60; constexpr int MOD = 1000000007; constexpr int MOD2 = 998244353; const int dx[4] = {1, 0, -1, 0}; const int dy[4] = {0, 1, 0, -1}; void Case(int i) { cout << "Case #" << i << ": "; } int popcount(int x) { return __builtin_popcount(x); } ll popcount(ll x) { return __builtin_popcountll(x); } #pragma endregion Macros #include using mint = atcoder::modint1000000007; #line 1 "/Users/siro53/kyo-pro/compro_library/data_structure/compress.hpp" template struct Compress { vector v; Compress() {} Compress(vector vv) : v(vv) { sort(ALL(v)); v.erase(unique(ALL(v)), end(v)); } void build(vector vv) { v = vv; sort(ALL(v)); v.erase(unique(ALL(v)), end(v)); } int get(T x) { return (int)(lower_bound(ALL(v), x) - v.begin()); } T &operator[](int i) { return v[i]; } size_t size() { return v.size(); } }; #line 1 "/Users/siro53/kyo-pro/compro_library/data_structure/BIT.hpp" template struct BIT { int n; vector bit; BIT(){} BIT(int _n) { init(_n); } void init(int _n) { n = _n + 1; bit.resize(n + 1, 0); } // [0, k) T sum(int k) { T res = 0; for(int i = k - 1; i >= 0; i = (i & (i + 1)) - 1) { res += bit[i]; } return res; } // [l, r) T sum(int l, int r) { return (l < r ? sum(r) - sum(l) : 0); } // bit[k] += x void add(int k, T x) { for(int i = k; i < n; i |= i + 1) { bit[i] += x; } } // v[0] + ... + v[res] >= x int lower_bound(T x) { int res = -1; int k = 1; while(2 * k <= n) { k <<= 1; } for(; k > 0; k >>= 1) { if(res + k < n && bit[res + k] < x) { x -= bit[res + k]; res += k; } } return res + 1; } }; #line 81 "main.cpp" int main() { int N, K; cin >> N >> K; vector a(N); REP(i, N) cin >> a[i]; Compress comp(a); int sz = SZ(comp); string s; cin >> s; auto isValid = [&](char c, int a1, int a2) -> bool { if(c == '<') { return (a1 < a2); } return (a1 > a2); }; vector dp(K+1, vector(N, 0)); REP(i, N) dp[0][i] = 1; REP(i, 1, K+1) { BIT bt(sz); REP(j, N) { if(s[i-1] == '<') { dp[i][j] = bt.sum(comp.get(a[j])); } else { dp[i][j] = bt.sum(comp.get(a[j]) + 1, sz); } bt.add(comp.get(a[j]), dp[i-1][j]); } } mint ans = 0; REP(j, N) ans += dp[K][j]; cout << ans.val() << endl; }