//#pragma GCC optimize("Ofast")
//#pragma GCC target("avx")
//#undef LOCAL




#include <algorithm>

#include <array>

#include <bitset>

#include <cassert>

#include <complex>

#include <cstdio>

#include <cstring>

#include <iostream>

#include <map>

#include <numeric>

#include <queue>

#include <set>

#include <string>

#include <unordered_map>

#include <unordered_set>

#include <vector>

using namespace std;

using uint = unsigned int;
using ll = long long;
using ull = unsigned long long;
constexpr ll TEN(int n) { return (n == 0) ? 1 : 10 * TEN(n - 1); }
template <class T> using V = vector<T>;
template <class T> using VV = V<V<T>>;


template <uint MD> struct ModInt {
    using M = ModInt;
    static constexpr uint get_mod() { return MD; }
    const static M G;
    uint v;
    ModInt(ll _v = 0) { set_v(uint(_v % MD + MD)); }
    M& set_v(uint _v) {
        v = (_v < MD) ? _v : _v - MD;
        return *this;
    }
    explicit operator bool() const { return v != 0; }
    M operator-() const { return M() - *this; }
    M operator+(const M& r) const { return M().set_v(v + r.v); }
    M operator-(const M& r) const { return M().set_v(v + MD - r.v); }
    M operator*(const M& r) const { return M().set_v(uint(ull(v) * r.v % MD)); }
    M operator/(const M& r) const { return *this * r.inv(); }
    M& operator+=(const M& r) { return *this = *this + r; }
    M& operator-=(const M& r) { return *this = *this - r; }
    M& operator*=(const M& r) { return *this = *this * r; }
    M& operator/=(const M& r) { return *this = *this / r; }
    bool operator==(const M& r) const { return v == r.v; }
    M pow(ll n) const {
        M x = *this, r = 1;
        while (n) {
            if (n & 1) r *= x;
            x *= x;
            n >>= 1;
        }
        return r;
    }
    M inv() const { return pow(MD - 2); }
    friend ostream& operator<<(ostream& os, const M& r) { return os << r.v; }
};
// using Mint = ModInt<998244353>;
// template<> const Mint Mint::G = Mint(3);




template <class Mint>
V<Mint> powTable(int n, Mint x) {
    V<Mint> table(n + 1);
    table[0] = Mint(1);
    for (int i = 1; i <= n; i++) {
        table[i] = table[i - 1] * x;
    }
    return table;
}

template<class Mint>
struct Comb {
    int max_n;
    V<Mint> fact, ifact;
    Comb() {}
    Comb(int n) : max_n(n) {
        fact = ifact = V<Mint>(n + 1);
        fact[0] = Mint(1);
        for (int i = 1; i <= n; i++) fact[i] = fact[i - 1] * i;
        ifact[n] = fact[n].inv();
        for (int i = n; i >= 1; i--) ifact[i - 1] = ifact[i] * i;
    }

    Mint C(int n, int k) {
        if (n < k || n < 0) return Mint(0);
        assert(0 <= k && k <= n && n <= max_n);
        return fact[n] * ifact[k] * ifact[n - k];
    }

    // n個の区別出来ないボールをk個の箱に入れる入れ方
    Mint H(int n, int k) {
        if (n == 0 && k == 0) return Mint(1);
        return C(n + k - 1, n);
    }
};



#include <unistd.h>

struct Scanner {
    int fd = -1;
    char line[(1 << 15) + 1];
    size_t st = 0, ed = 0;
    void reread() {
        memmove(line, line + st, ed - st);
        ed -= st;
        st = 0;
        ed += ::read(fd, line + ed, (1 << 15) - ed);
        line[ed] = '\0';
    }
    bool succ() {
        while (true) {
            if (st == ed) {
                reread();
                if (st == ed) return false;
            }
            while (st != ed && isspace(line[st])) st++;
            if (st != ed) break;
        }
        if (ed - st <= 50) {
            bool sep = false;
            for (size_t i = st; i < ed; i++) {
                if (isspace(line[i])) {
                    sep = true;
                    break;
                }
            }
            if (!sep) reread();
        }
        return true;
    }
    template <class T, enable_if_t<is_same<T, string>::value, int> = 0>
    bool read_single(T& ref) {
        if (!succ()) return false;
        while (true) {
            size_t sz = 0;
            while (st + sz < ed && !isspace(line[st + sz])) sz++;
            ref.append(line + st, sz);
            st += sz;
            if (!sz || st != ed) break;
            reread();
        }
        return true;
    }
    template <class T, enable_if_t<is_integral<T>::value, int> = 0>
    bool read_single(T& ref) {
        if (!succ()) return false;
        bool neg = false;
        if (line[st] == '-') {
            neg = true;
            st++;
        }
        ref = T(0);
        while (isdigit(line[st])) {
            ref = 10 * ref + (line[st++] & 0xf);
        }
        if (neg) ref = -ref;
        return true;
    }
    template <class T> bool read_single(V<T>& ref) {
        for (auto& d : ref) {
            if (!read_single(d)) return false;
        }
        return true;
    }
    void read() {}
    template <class H, class... T> void read(H& h, T&... t) {
        bool f = read_single(h);
        assert(f);
        read(t...);
    }
    Scanner(FILE* fp) : fd(fileno(fp)) {}
};

struct Printer {
  public:
    template <bool F = false> void write() {}
    template <bool F = false, class H, class... T>
    void write(const H& h, const T&... t) {
        if (F) write_single(' ');
        write_single(h);
        write<true>(t...);
    }
    template <class... T> void writeln(const T&... t) {
        write(t...);
        write_single('\n');
    }

    Printer(FILE* _fp) : fp(_fp) {}
    ~Printer() { flush(); }

  private:
    static constexpr size_t SIZE = 1 << 15;
    FILE* fp;
    char line[SIZE], small[50];
    size_t pos = 0;
    void flush() {
        fwrite(line, 1, pos, fp);
        pos = 0;
    }
    void write_single(const char& val) {
        if (pos == SIZE) flush();
        line[pos++] = val;
    }
    template <class T, enable_if_t<is_integral<T>::value, int> = 0>
    void write_single(T val) {
        if (pos > (1 << 15) - 50) flush();
        if (val == 0) {
            write_single('0');
            return;
        }
        if (val < 0) {
            write_single('-');
            val = -val; // todo min
        }
        size_t len = 0;
        while (val) {
            small[len++] = char(0x30 | (val % 10));
            val /= 10;
        }
        for (size_t i = 0; i < len; i++) {
            line[pos + i] = small[len - 1 - i];
        }
        pos += len;
    }
    void write_single(const string& s) {
        for (char c : s) write_single(c);
    }
    void write_single(const char* s) {
        size_t len = strlen(s);
        for (size_t i = 0; i < len; i++) write_single(s[i]);
    }
    template <class T> void write_single(const V<T>& val) {
        auto n = val.size();
        for (size_t i = 0; i < n; i++) {
            if (i) write_single(' ');
            write_single(val[i]);
        }
    }
};



// bit op
int popcnt(uint x) { return __builtin_popcount(x); }
int popcnt(ull x) { return __builtin_popcountll(x); }
int bsr(uint x) { return 31 - __builtin_clz(x); }
int bsr(ull x) { return 63 - __builtin_clzll(x); }
int bsf(uint x) { return __builtin_ctz(x); }
int bsf(ull x) { return __builtin_ctzll(x); }


struct DynamicModInt {
    using M = DynamicModInt;

  private:
    static uint MD;
    static ull iMD;
    uint v = 0;

  public:
    static void set_mod(uint _MD) {
        assert(2 <= _MD);
        MD = _MD;
        iMD = ull(-1) / _MD + 1;
    }
    DynamicModInt() {}
    DynamicModInt(ll _v) { set_v(uint(_v % MD + MD)); }
    uint val() const { return v; }
    M& set_v(uint _v) {
        v = (_v < MD) ? _v : _v - MD;
        return *this;
    }
    explicit operator bool() const { return v != 0; }
    M operator-() const { return M() - *this; }
    M operator+(const M& r) const { return M().set_v(v + r.v); }
    M operator-(const M& r) const { return M().set_v(v + MD - r.v); }
    /*
    u32 fact_fast(u32 n, u32 mod) {
      u64 imod = u64(-1) / mod + 1; // ceil((1<<64) / mod);
      auto mul_mod = [&](u32 a, u32 b) {
        u64 c = u64(a) * b;
        u64 d = (__uint128_t(c) * imod) >> 64;
        u64 e = (c - d * mod + mod);
        //return e;
        return (e < mod) ? e : e - mod;
      };
      u32 ret = 1;
      for (int i = 1; i <= n; ++i) ret = mul_mod(ret, i);
      return ret;
    }
    */
    M operator*(const M& r) const {
        ull c = ull(v) * r.v;
        ull d = (__uint128_t(c) * iMD) >> 64;
        return M().set_v(uint(c - d * MD + MD));
    }
    M operator/(const M& r) const { return *this * r.inv(); }
    M& operator+=(const M& r) { return *this = *this + r; }
    M& operator-=(const M& r) { return *this = *this - r; }
    M& operator*=(const M& r) { return *this = *this * r; }
    M& operator/=(const M& r) { return *this = *this / r; }
    bool operator==(const M& r) const { return v == r.v; }
    M pow(ll n) const {
        M x = *this, r = 1;
        while (n) {
            if (n & 1) r *= x;
            x *= x;
            n >>= 1;
        }
        return r;
    }
    M inv() const {
        pair<uint, ll> p = {MD, 0}, q = {v, 1};
        while (q.first) {
            uint t = p.first / q.first;
            p.first -= t * q.first;
            p.second -= t * q.second;
            swap(p, q);
        }
        return M(p.second);
    }
    friend ostream& operator<<(ostream& os, const M& r) { return os << r.v; }
};
uint DynamicModInt::MD;
ull DynamicModInt::iMD;
using Mint = DynamicModInt;

Scanner sc = Scanner(stdin);
Printer pr = Printer(stdout);

int main() {
    Mint::set_mod(TEN(9) + 7);
    V<Mint> p2 = powTable(10000, Mint(2));
    int n, m;
    sc.read(n, m);

    V<Mint> dp(m + 1);
    dp[m] = Mint(1);

    for (int ph = 0; ph < n; ph++) {
        V<Mint> ndp(m + 1);
        Mint sm = 0;
        for (int j = m; j >= 1; j--) {
            ndp[j] = Mint(j) * sm + dp[j] * Mint(j + 1);
            sm *= Mint(2);
            sm += dp[j];
        }
        dp = ndp;
/*        for (int j = 1; j <= m; j++) {
            for (int k = 1; k < j; k++) {
                // j -> k
                dp[k] += dp[j] * Mint(k) * p2[j - k - 1];
            }
            dp[j] *= Mint(j + 1);
        }*/
    }
           ;
    Mint sm = 0;
    for (auto x: dp) {
        sm += x;
    }
    pr.writeln(sm.val());
    return 0;
}


Measured memory_bytes: 3744