n,a,b=map(int,input().split())
num9=10**9+7
num2=pow(2,n,num9)-1
def cul(num1,num2):
    num=1
    for i in range(num1-num2+1,n+1):
        num*=i
        num%=num9
    for i in range(1,num2+1):
        num*=pow(i,num9-2,num9)
        num%=num9
    return num
print((num2-cul(n,a)-cul(n,b))%num9) n,a,b=map(int,input().split()) n map(int,input().split()) map int input().split() ().split () input split a b num9=10**9+7 num9 10**9+7 10**9 10 9 7 num2=pow(2,n,num9)-1 num2 pow(2,n,num9)-1 pow(2,n,num9) pow 2 n num9 1 def cul(num1,num2):
    num=1
    for i in range(num1-num2+1,n+1):
        num*=i
        num%=num9
    for i in range(1,num2+1):
        num*=pow(i,num9-2,num9)
        num%=num9
    return num cul num=1 num 1 for i in range(num1-num2+1,n+1):
        num*=i
        num%=num9
     i range(num1-num2+1,n+1) range num1-num2+1 num1-num2 num1 num2 1 n+1 n 1 num*=i num i num%=num9 num num9 for i in range(1,num2+1):
        num*=pow(i,num9-2,num9)
        num%=num9
     i range(1,num2+1) range 1 num2+1 num2 1 num*=pow(i,num9-2,num9) num pow(i,num9-2,num9) pow i num9-2 num9 2 num9 num%=num9 num num9 return num num num1 num1 num2 num2 print((num2-cul(n,a)-cul(n,b))%num9) print (num2-cul(n,a)-cul(n,b))%num9 num2-cul(n,a)-cul(n,b) num2-cul(n,a) num2 cul(n,a) cul n a cul(n,b) cul n b num9 b=map(int,input().split()) map(int,input().split()) b def cul(num1,num2):
    num=1
    for i in range(num1-num2+1,n+1):
        num*=i
        num%=num9
    for i in range(1,num2+1):
        num*=pow(i,num9-2,num9)
        num%=num9
    return num def cul(num1,num2):
    num=1
    for i in range(num1-num2+1,n+1):
        num*=i
        num%=num9
    for i in range(1,num2+1):
        num*=pow(i,num9-2,num9)
        num%=num9
    return num cul a,b=map(int,input().split()) map(int,input().split()) a n,a,b=map(int,input().split()) map(int,input().split()) n num9=10**9+7 10**9+7 num9 num2=pow(2,n,num9)-1 pow(2,n,num9)-1 num2
n,a,b=map(int,input().split())
num9=10**9+7
num2=pow(2,n,num9)-1
def cul(num1,num2):
    num=1
    for i in range(num1-num2+1,n+1):
        num*=i
        num%=num9
    for i in range(1,num2+1):
        num*=pow(i,num9-2,num9)
        num%=num9
    return num
print((num2-cul(n,a)-cul(n,b))%num9)
