N,M=map(int,input().split()) mod=10**9+7 FACT=[1] for i in range(1,2*10**5+1): FACT.append(FACT[-1]*i%mod) FACT_INV=[pow(FACT[-1],mod-2,mod)] for i in range(2*10**5,0,-1): FACT_INV.append(FACT_INV[-1]*i%mod) FACT_INV.reverse() def Combi(a,b): if 0<=b<=a: return FACT[a]*FACT_INV[b]*FACT_INV[a-b]%mod else: return 0 ANS=0 for i in range(N,M+1): ANS=(ANS+Combi(i,N))%mod print(ANS)