n, a, b = map(int, input().split())

MOD = 10**9 + 7

def comb(n, r, mod):
    if r > n-r:
        r = n - r
    
    res_X = 1
    for i in range(n-r+1, n+1):
        res_X = (res_X * i)%mod
    
    res_Y = 1
    for i in range(1, r+1):
        res_Y = (res_Y * i)%mod
    
    return (res_X * pow(res_Y, mod-2, mod))%mod

base = (pow(2, n, MOD) - 1)%MOD
a = comb(n, a, MOD)
b = comb(n, b, MOD)

print((base - a - b)%MOD) n, a, b = map(int, input().split()) n map(int, input().split()) map int input().split() ().split () input split a b MOD = 10**9 + 7 MOD 10**9 + 7 10**9 10 9 7 def comb(n, r, mod):
    if r > n-r:
        r = n - r
    
    res_X = 1
    for i in range(n-r+1, n+1):
        res_X = (res_X * i)%mod
    
    res_Y = 1
    for i in range(1, r+1):
        res_Y = (res_Y * i)%mod
    
    return (res_X * pow(res_Y, mod-2, mod))%mod comb if r > n-r:
        r = n - r
    
     r > n-r r n-r n r r = n - r r n - r n r res_X = 1 res_X 1 for i in range(n-r+1, n+1):
        res_X = (res_X * i)%mod
    
     i range(n-r+1, n+1) range n-r+1 n-r n r 1 n+1 n 1 res_X = (res_X * i)%mod res_X (res_X * i)%mod res_X * i res_X i mod res_Y = 1 res_Y 1 for i in range(1, r+1):
        res_Y = (res_Y * i)%mod
    
     i range(1, r+1) range 1 r+1 r 1 res_Y = (res_Y * i)%mod res_Y (res_Y * i)%mod res_Y * i res_Y i mod return (res_X * pow(res_Y, mod-2, mod))%mod (res_X * pow(res_Y, mod-2, mod))%mod res_X * pow(res_Y, mod-2, mod) res_X pow(res_Y, mod-2, mod) pow res_Y mod-2 mod 2 mod mod n n r r mod mod base = (pow(2, n, MOD) - 1)%MOD base (pow(2, n, MOD) - 1)%MOD pow(2, n, MOD) - 1 pow(2, n, MOD) pow 2 n MOD 1 MOD a = comb(n, a, MOD) a comb(n, a, MOD) comb n a MOD b = comb(n, b, MOD) b comb(n, b, MOD) comb n b MOD print((base - a - b)%MOD) print (base - a - b)%MOD base - a - b base - a base a b MOD b = map(int, input().split()) map(int, input().split()) b b = comb(n, b, MOD) comb(n, b, MOD) b n, a, b = map(int, input().split()) map(int, input().split()) n a = comb(n, a, MOD) comb(n, a, MOD) a def comb(n, r, mod):
    if r > n-r:
        r = n - r
    
    res_X = 1
    for i in range(n-r+1, n+1):
        res_X = (res_X * i)%mod
    
    res_Y = 1
    for i in range(1, r+1):
        res_Y = (res_Y * i)%mod
    
    return (res_X * pow(res_Y, mod-2, mod))%mod def comb(n, r, mod):
    if r > n-r:
        r = n - r
    
    res_X = 1
    for i in range(n-r+1, n+1):
        res_X = (res_X * i)%mod
    
    res_Y = 1
    for i in range(1, r+1):
        res_Y = (res_Y * i)%mod
    
    return (res_X * pow(res_Y, mod-2, mod))%mod comb a, b = map(int, input().split()) map(int, input().split()) a MOD = 10**9 + 7 10**9 + 7 MOD base = (pow(2, n, MOD) - 1)%MOD (pow(2, n, MOD) - 1)%MOD base
n, a, b = map(int, input().split())

MOD = 10**9 + 7

def comb(n, r, mod):
    if r > n-r:
        r = n - r
    
    res_X = 1
    for i in range(n-r+1, n+1):
        res_X = (res_X * i)%mod
    
    res_Y = 1
    for i in range(1, r+1):
        res_Y = (res_Y * i)%mod
    
    return (res_X * pow(res_Y, mod-2, mod))%mod

base = (pow(2, n, MOD) - 1)%MOD
a = comb(n, a, MOD)
b = comb(n, b, MOD)

print((base - a - b)%MOD)