MOD = 10**9 + 7

def modpow(a: int, p: int, mod: int) -> int:
    # return a**p (mod MOD) O(log p)
    res = 1
    while p > 0:
        if p & 1 > 0:
            res = res * a % mod
        a = a**2 % mod
        p >>= 1
    return res

def comb(N, x):
    numerator = 1
    for i in range(N-x+1, N+1):
        numerator = numerator * i % MOD
    denominator = 1
    for j in range(1, x+1):
        denominator = denominator * j % MOD
    d = modpow(denominator, MOD-2, MOD)
    return numerator * d
    
n,a,b=map(int,input().split())

ans = (modpow(2,n,MOD)-1 - comb(n,a) - comb(n,b)) % MOD
print(ans) MOD = 10**9 + 7 MOD 10**9 + 7 10**9 10 9 7 def modpow(a: int, p: int, mod: int) -> int:
    # return a**p (mod MOD) O(log p)
    res = 1
    while p > 0:
        if p & 1 > 0:
            res = res * a % mod
        a = a**2 % mod
        p >>= 1
    return res modpow res = 1 res 1 while p > 0:
        if p & 1 > 0:
            res = res * a % mod
        a = a**2 % mod
        p >>= 1
     p > 0 p 0 if p & 1 > 0:
            res = res * a % mod
         p & 1 > 0 p & 1 p 1 0 res = res * a % mod res res * a % mod res * a res a mod a = a**2 % mod a a**2 % mod a**2 a 2 mod p >>= 1 p 1 return res res a: int a p: int p mod: int mod def comb(N, x):
    numerator = 1
    for i in range(N-x+1, N+1):
        numerator = numerator * i % MOD
    denominator = 1
    for j in range(1, x+1):
        denominator = denominator * j % MOD
    d = modpow(denominator, MOD-2, MOD)
    return numerator * d
     comb numerator = 1 numerator 1 for i in range(N-x+1, N+1):
        numerator = numerator * i % MOD
     i range(N-x+1, N+1) range N-x+1 N-x N x 1 N+1 N 1 numerator = numerator * i % MOD numerator numerator * i % MOD numerator * i numerator i MOD denominator = 1 denominator 1 for j in range(1, x+1):
        denominator = denominator * j % MOD
     j range(1, x+1) range 1 x+1 x 1 denominator = denominator * j % MOD denominator denominator * j % MOD denominator * j denominator j MOD d = modpow(denominator, MOD-2, MOD) d modpow(denominator, MOD-2, MOD) modpow denominator MOD-2 MOD 2 MOD return numerator * d numerator * d numerator d N N x x n,a,b=map(int,input().split()) n map(int,input().split()) map int input().split() ().split () input split a b ans = (modpow(2,n,MOD)-1 - comb(n,a) - comb(n,b)) % MOD ans (modpow(2,n,MOD)-1 - comb(n,a) - comb(n,b)) % MOD modpow(2,n,MOD)-1 - comb(n,a) - comb(n,b) modpow(2,n,MOD)-1 - comb(n,a) modpow(2,n,MOD)-1 modpow(2,n,MOD) modpow 2 n MOD 1 comb(n,a) comb n a comb(n,b) comb n b MOD print(ans) print ans n,a,b=map(int,input().split()) map(int,input().split()) n ans = (modpow(2,n,MOD)-1 - comb(n,a) - comb(n,b)) % MOD (modpow(2,n,MOD)-1 - comb(n,a) - comb(n,b)) % MOD ans b=map(int,input().split()) map(int,input().split()) b MOD = 10**9 + 7 10**9 + 7 MOD a,b=map(int,input().split()) map(int,input().split()) a def modpow(a: int, p: int, mod: int) -> int:
    # return a**p (mod MOD) O(log p)
    res = 1
    while p > 0:
        if p & 1 > 0:
            res = res * a % mod
        a = a**2 % mod
        p >>= 1
    return res def modpow(a: int, p: int, mod: int) -> int:
    # return a**p (mod MOD) O(log p)
    res = 1
    while p > 0:
        if p & 1 > 0:
            res = res * a % mod
        a = a**2 % mod
        p >>= 1
    return res modpow def comb(N, x):
    numerator = 1
    for i in range(N-x+1, N+1):
        numerator = numerator * i % MOD
    denominator = 1
    for j in range(1, x+1):
        denominator = denominator * j % MOD
    d = modpow(denominator, MOD-2, MOD)
    return numerator * d
     def comb(N, x):
    numerator = 1
    for i in range(N-x+1, N+1):
        numerator = numerator * i % MOD
    denominator = 1
    for j in range(1, x+1):
        denominator = denominator * j % MOD
    d = modpow(denominator, MOD-2, MOD)
    return numerator * d
     comb
MOD = 10**9 + 7

def modpow(a: int, p: int, mod: int) -> int:
    # return a**p (mod MOD) O(log p)
    res = 1
    while p > 0:
        if p & 1 > 0:
            res = res * a % mod
        a = a**2 % mod
        p >>= 1
    return res

def comb(N, x):
    numerator = 1
    for i in range(N-x+1, N+1):
        numerator = numerator * i % MOD
    denominator = 1
    for j in range(1, x+1):
        denominator = denominator * j % MOD
    d = modpow(denominator, MOD-2, MOD)
    return numerator * d
    
n,a,b=map(int,input().split())

ans = (modpow(2,n,MOD)-1 - comb(n,a) - comb(n,b)) % MOD
print(ans)