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

m=10**9+7

def c(x,r=1):

 for i in range(x):r=r*(n-i)*pow(i+1,m-2,m)%m

 return r

print(((pow(2,n,m)-1-c(a)-c(b))%m))
n,a,b=list(map(int,input().split()))

m=10**9+7

s=r=1

for i in range(b):

 r=r*(n-i)*pow(i+1,m-2,m)%m

 if i+1in[a,b]:s+=r

print(((pow(2,n,m)-s)%m))
n, a, b = list(map(int, input().split()))
m = 10**9 + 7


def c(x, r=1):
    for i in range(x):
        r = r * (n - i) * pow(i + 1, m - 2, m) % m
    return r


print(((pow(2, n, m) - 1 - c(a) - c(b)) % m))

n, a, b = list(map(int, input().split()))
m = 10**9 + 7
s = r = 1
for i in range(b):
    r = r * (n - i) * pow(i + 1, m - 2, m) % m
    if i + 1 in [a, b]:
        s += r
print(((pow(2, n, m) - s) % m))

- - -def c(x, r=1): -    for i in range(x): -        r = r * (n - i) * pow(i + 1, m - 2, m) % m -    return r - - -print(((pow(2, n, m) - 1 - c(a) - c(b)) % m)) +s = r = 1 +for i in range(b): +    r = r * (n - i) * pow(i + 1, m - 2, m) % m +    if i + 1 in [a, b]: +        s += r +print(((pow(2, n, m) - s) % m))