def calc_comb(n,r):
    numerator=1
    for i in range(n-r+1,n+1):
        numerator=(numerator*i)%mod
    denominator=1
    for i in range(1,r+1):
        denominator=(denominator*i)%mod
    return (numerator*pow(denominator,mod-2,mod))%mod
n,a,b=map(int,input().split())
mod=1000000007
print((pow(2,n,mod)-1-calc_comb(n,a)-calc_comb(n,b)+mod)%mod)
 def calc_comb(n,r):
    numerator=1
    for i in range(n-r+1,n+1):
        numerator=(numerator*i)%mod
    denominator=1
    for i in range(1,r+1):
        denominator=(denominator*i)%mod
    return (numerator*pow(denominator,mod-2,mod))%mod calc_comb numerator=1 numerator 1 for i in range(n-r+1,n+1):
        numerator=(numerator*i)%mod
     i range(n-r+1,n+1) range n-r+1 n-r n r 1 n+1 n 1 numerator=(numerator*i)%mod numerator (numerator*i)%mod numerator*i numerator i mod denominator=1 denominator 1 for i in range(1,r+1):
        denominator=(denominator*i)%mod
     i range(1,r+1) range 1 r+1 r 1 denominator=(denominator*i)%mod denominator (denominator*i)%mod denominator*i denominator i mod return (numerator*pow(denominator,mod-2,mod))%mod (numerator*pow(denominator,mod-2,mod))%mod numerator*pow(denominator,mod-2,mod) numerator pow(denominator,mod-2,mod) pow denominator mod-2 mod 2 mod mod n n r r n,a,b=map(int,input().split()) n map(int,input().split()) map int input().split() ().split () input split a b mod=1000000007 mod 1000000007 print((pow(2,n,mod)-1-calc_comb(n,a)-calc_comb(n,b)+mod)%mod) print (pow(2,n,mod)-1-calc_comb(n,a)-calc_comb(n,b)+mod)%mod pow(2,n,mod)-1-calc_comb(n,a)-calc_comb(n,b)+mod pow(2,n,mod)-1-calc_comb(n,a)-calc_comb(n,b) pow(2,n,mod)-1-calc_comb(n,a) pow(2,n,mod)-1 pow(2,n,mod) pow 2 n mod 1 calc_comb(n,a) calc_comb n a calc_comb(n,b) calc_comb n b mod mod a,b=map(int,input().split()) map(int,input().split()) a mod=1000000007 1000000007 mod n,a,b=map(int,input().split()) map(int,input().split()) n b=map(int,input().split()) map(int,input().split()) b def calc_comb(n,r):
    numerator=1
    for i in range(n-r+1,n+1):
        numerator=(numerator*i)%mod
    denominator=1
    for i in range(1,r+1):
        denominator=(denominator*i)%mod
    return (numerator*pow(denominator,mod-2,mod))%mod def calc_comb(n,r):
    numerator=1
    for i in range(n-r+1,n+1):
        numerator=(numerator*i)%mod
    denominator=1
    for i in range(1,r+1):
        denominator=(denominator*i)%mod
    return (numerator*pow(denominator,mod-2,mod))%mod calc_comb
def calc_comb(n,r):
    numerator=1
    for i in range(n-r+1,n+1):
        numerator=(numerator*i)%mod
    denominator=1
    for i in range(1,r+1):
        denominator=(denominator*i)%mod
    return (numerator*pow(denominator,mod-2,mod))%mod
n,a,b=map(int,input().split())
mod=1000000007
print((pow(2,n,mod)-1-calc_comb(n,a)-calc_comb(n,b)+mod)%mod)

