#include using namespace std; typedef long long ll; typedef vector vll; typedef vector vvll; typedef pair P; typedef string str; typedef vector

vp; typedef vector vs; typedef vector vb; const ll mod=1e9+7; const ll inf=1e18; #define rep(i,m,n) for(ll i=m;i=n;i--) #define fi first #define se second #define chmax(x,y) x=max(x,y) #define chmin(x,y) x=min(x,y) #define eb(x) emplace_back(x) #define pb(x) pop_back(x) #define all(x) x.begin(),x.end() #define allr(x) x.rbegin(),x.rend() #define sum(x) accumulate(all(x),0) #define lb(x,a) lower_bound(all(x),a) #define ub(x,a) upper_bound(all(x),a) #define maxe(x,a) max_element(all(x)) #define mine(x,a) min_element(all(x)) #define pc(x) __builtin_popcount(x) #define gll greater() struct mint { ll x; // typedef long long ll; mint(ll x=0):x((x%mod+mod)%mod){} mint operator-() const { return mint(-x);} mint& operator+=(const mint a) { if ((x += a.x) >= mod) x -= mod; return *this; } mint& operator-=(const mint a) { if ((x += mod-a.x) >= mod) x -= mod; return *this; } mint& operator*=(const mint a) { (x *= a.x) %= mod; return *this;} mint operator+(const mint a) const { return mint(*this) += a;} mint operator-(const mint a) const { return mint(*this) -= a;} mint operator*(const mint a) const { return mint(*this) *= 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(mod-2);} mint& operator/=(const mint a) { return *this *= a.inv();} mint operator/(const mint a) const { return mint(*this) /= a;} }; istream& operator>>(istream& is, mint& a) { return is >> a.x;} ostream& operator<<(ostream& os, const mint& a) { return os << a.x;} const ll nmax=1000005; ll fac[nmax],finv[nmax],inv[nmax]; void comint(){ fac[0]=fac[1]=1; finv[0]=finv[1]=1; inv[1]=1; for(ll i=2;i> n >> m; mint ans=0; comint(); rep(i,n,m+1) ans+=com(i,n); cout << ans << endl; } int main(){ cin.tie(nullptr); ios::sync_with_stdio(false); solve(); }