m=10**9+7
n,a,b=map(int,input().split())

def comb(n,r,m):
    x,y=1,1
    for i in range(r):
        x*=n-i
        y*=i+1
        x%=m
        y%=m
    return int(x * pow(y, m-2, m))
ans = pow(2, n, m)-1-comb(n, a, m) - comb(n, b, m)
print(ans%m) m=10**9+7 m 10**9+7 10**9 10 9 7 n,a,b=map(int,input().split()) n map(int,input().split()) map int input().split() ().split () input split a b def comb(n,r,m):
    x,y=1,1
    for i in range(r):
        x*=n-i
        y*=i+1
        x%=m
        y%=m
    return int(x * pow(y, m-2, m)) comb x,y=1,1 x 1 y 1 for i in range(r):
        x*=n-i
        y*=i+1
        x%=m
        y%=m
     i range(r) range r x*=n-i x n-i n i y*=i+1 y i+1 i 1 x%=m x m y%=m y m return int(x * pow(y, m-2, m)) int(x * pow(y, m-2, m)) int x * pow(y, m-2, m) x pow(y, m-2, m) pow y m-2 m 2 m n n r r m m ans = pow(2, n, m)-1-comb(n, a, m) - comb(n, b, m) ans pow(2, n, m)-1-comb(n, a, m) - comb(n, b, m) pow(2, n, m)-1-comb(n, a, m) pow(2, n, m)-1 pow(2, n, m) pow 2 n m 1 comb(n, a, m) comb n a m comb(n, b, m) comb n b m print(ans%m) print ans%m ans m def comb(n,r,m):
    x,y=1,1
    for i in range(r):
        x*=n-i
        y*=i+1
        x%=m
        y%=m
    return int(x * pow(y, m-2, m)) def comb(n,r,m):
    x,y=1,1
    for i in range(r):
        x*=n-i
        y*=i+1
        x%=m
        y%=m
    return int(x * pow(y, m-2, m)) comb b=map(int,input().split()) map(int,input().split()) b ans = pow(2, n, m)-1-comb(n, a, m) - comb(n, b, m) pow(2, n, m)-1-comb(n, a, m) - comb(n, b, m) ans m=10**9+7 10**9+7 m a,b=map(int,input().split()) map(int,input().split()) a n,a,b=map(int,input().split()) map(int,input().split()) n
m=10**9+7
n,a,b=map(int,input().split())

def comb(n,r,m):
    x,y=1,1
    for i in range(r):
        x*=n-i
        y*=i+1
        x%=m
        y%=m
    return int(x * pow(y, m-2, m))
ans = pow(2, n, m)-1-comb(n, a, m) - comb(n, b, m)
print(ans%m)