import sys
input = lambda :sys.stdin.readline()[:-1]
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
sys.setrecursionlimit(10**7)
yes = lambda :print("yes");Yes = lambda :print("Yes");YES = lambda : print("YES")
no = lambda :print("no");No = lambda :print("No");NO = lambda : print("NO")
#######################################################################

n = ni()
p = na()
mod = 10**9+7
a,b,c = 0,0,0
for i in p:
    if i<50:
        a+=1
    elif i==50:
        b+=1
    else:
        c+=1
ans = pow(2,a+c,mod)-pow(2,a,mod)*pow(2,max(c-1,0),mod)
print(ans%mod)