n,a,b = map(int,input().split())
m = 10**9 + 7
comb_a = 1
comb_b = 1

a_num = list(range(1,a+1))
j = 0
for i in range(1,a+1):
    comb_a *= (n-i+1)
    comb_a *= pow(a_num[i-1],m-2,m)
    comb_a = comb_a % m

b_num = list(range(1,b+1))
j = 0
for i in range(1,b+1):
    comb_b *= (n-i+1)
    comb_b *= pow(b_num[i-1],m-2,m)
    comb_b = comb_b % m

ans = pow(2,n,m) - comb_a - comb_b - 1
print(int(ans) % m) n,a,b = map(int,input().split()) n map(int,input().split()) map int input().split() ().split () input split a b m = 10**9 + 7 m 10**9 + 7 10**9 10 9 7 comb_a = 1 comb_a 1 comb_b = 1 comb_b 1 a_num = list(range(1,a+1)) a_num list(range(1,a+1)) list range(1,a+1) range 1 a+1 a 1 j = 0 j 0 for i in range(1,a+1):
    comb_a *= (n-i+1)
    comb_a *= pow(a_num[i-1],m-2,m)
    comb_a = comb_a % m i range(1,a+1) range 1 a+1 a 1 comb_a *= (n-i+1) comb_a n-i+1 n-i n i 1 comb_a *= pow(a_num[i-1],m-2,m) comb_a pow(a_num[i-1],m-2,m) pow a_num[i-1] a_num i-1 i 1 m-2 m 2 m comb_a = comb_a % m comb_a comb_a % m comb_a m b_num = list(range(1,b+1)) b_num list(range(1,b+1)) list range(1,b+1) range 1 b+1 b 1 j = 0 j 0 for i in range(1,b+1):
    comb_b *= (n-i+1)
    comb_b *= pow(b_num[i-1],m-2,m)
    comb_b = comb_b % m i range(1,b+1) range 1 b+1 b 1 comb_b *= (n-i+1) comb_b n-i+1 n-i n i 1 comb_b *= pow(b_num[i-1],m-2,m) comb_b pow(b_num[i-1],m-2,m) pow b_num[i-1] b_num i-1 i 1 m-2 m 2 m comb_b = comb_b % m comb_b comb_b % m comb_b m ans = pow(2,n,m) - comb_a - comb_b - 1 ans pow(2,n,m) - comb_a - comb_b - 1 pow(2,n,m) - comb_a - comb_b pow(2,n,m) - comb_a pow(2,n,m) pow 2 n m comb_a comb_b 1 print(int(ans) % m) print int(ans) % m int(ans) int ans m comb_a *= pow(a_num[i-1],m-2,m) pow(a_num[i-1],m-2,m) comb_a j = 0 0 j ans = pow(2,n,m) - comb_a - comb_b - 1 pow(2,n,m) - comb_a - comb_b - 1 ans b_num = list(range(1,b+1)) list(range(1,b+1)) b_num comb_b = 1 1 comb_b comb_a = comb_a % m comb_a % m comb_a comb_b = comb_b % m comb_b % m comb_b m = 10**9 + 7 10**9 + 7 m b = map(int,input().split()) map(int,input().split()) b j = 0 0 j comb_a = 1 1 comb_a n,a,b = map(int,input().split()) map(int,input().split()) n comb_a *= (n-i+1) n-i+1 comb_a a,b = map(int,input().split()) map(int,input().split()) a a_num = list(range(1,a+1)) list(range(1,a+1)) a_num comb_b *= (n-i+1) n-i+1 comb_b comb_b *= pow(b_num[i-1],m-2,m) pow(b_num[i-1],m-2,m) comb_b
n,a,b = map(int,input().split())
m = 10**9 + 7
comb_a = 1
comb_b = 1

a_num = list(range(1,a+1))
j = 0
for i in range(1,a+1):
    comb_a *= (n-i+1)
    comb_a *= pow(a_num[i-1],m-2,m)
    comb_a = comb_a % m

b_num = list(range(1,b+1))
j = 0
for i in range(1,b+1):
    comb_b *= (n-i+1)
    comb_b *= pow(b_num[i-1],m-2,m)
    comb_b = comb_b % m

ans = pow(2,n,m) - comb_a - comb_b - 1
print(int(ans) % m)