#include<bits/stdc++.h>
//#include<atcoder/all>
using namespace std;
//using namespace atcoder;
#define rep(i,n) for(ll i=0; i<n; i++)
#define rrep(i,n) for(ll i=n-1; i>=0; i--)
#define print(a) cout<<a<<endl
typedef long long ll;
#define yn(flg) if(flg){cout<<"Yes"<<endl;}else{cout<<"No"<<endl;}
#define YN(flg) if(flg){cout<<"YES"<<endl;}else{cout<<"NO"<<endl;}
#define so(a) sort(a.begin(),a.end())
#define mp make_pair
#define vi vector<int>
#define vl vector<ll>
#define vs vector<string>
#define pb push_back
#define a2i(a,s) (ll)(a-s)
#define i2a(s,a) (char)(s+a)
#define ssize(a) a.size()
typedef pair<int, int> Pii;
typedef pair<int, ll> Pil;
typedef pair<pair<ll,ll>,ll> P3;
typedef pair<pair<ll,ll>,pair<ll,ll>> P4;
typedef pair<ll, ll> Pll;
typedef pair<ll,Pll> Plll;
typedef pair<Pii, int> Piii;
const ll INF = 1000000000000000000;
template<class T> inline bool chmin(T& a, T b) {
if (a > b) {
a = b;
return true;
}
return false;
}
template<class T> inline bool chmax(T& a, T b) {
if (a < b) {
a = b;
return true;
}
return false;
}
ll MOD=1000000007;
int main(){
//入力
cin.tie(0);
ios::sync_with_stdio(0);
ll h,w;
cin>>w>>h;
//判定１
if(w<h*h){
vector<ll> ALL(w+1,1);
ALL[1]=1;
for(ll i=2;i<=w;i++){
ALL[i]=(ALL[i-1]+ALL[i-2])%MOD;
}
for(ll i=1;i<=w;i++){
ll p=ALL[i];
for(ll j=1;j<h;j++)p=(p*ALL[i])%MOD;
ALL[i]=p;
}
vector<ll> dp(w+1,0);
dp[1]=1;
for(ll j=1;j<=w;j++){
ll sum=0;
for(ll k=1;k<j;k++){
ll dame=(dp[k]*ALL[j-k])%MOD;
sum=(sum+dame)%MOD;
}
dp[j]=(ALL[j]-sum+MOD)%MOD;
}
cout<<dp[w]<<endl;
}else{
vector<vector<ll> > dp(w+1,vector<ll>(h+1,0));
vector<vector<ll> > c(h+1,vector<ll>(h+1,0));
for(ll i=1;i<=h;i++){
for(ll j=0;j<=i;j++){
if(j==0)c[i][j]=1;
else if(j==1)c[i][j]=i;
else {
c[i][j]=(c[i-1][j]+c[i-1][j-1])%MOD;
}
// cout<<c[i][j]<<" ";
}
// cout<<endl;
}
for(ll i=1;i<w;i++){
for(ll j=1;j<=h;j++){
ll p=0;
if(i==1){
dp[i][j]=c[h][j];
}else{
for(ll k=1;k<=h;k++){
if(h-k<j)break;
p=(p+dp[i-1][k]*c[h-k][j])%MOD;
}
dp[i][j]=p;
}
}
}
ll sum=0;
for(ll i=1;i<=h;i++)sum=(sum+dp[w-1][i])%MOD;
cout<<sum<<endl;
}
return 0;
}
