local bor = bit.bor local mod = 1000000007 local mfl = math.floor local function bmul(x, y) local x1, y1 = mfl(x / 31623), mfl(y / 31623) local x0, y0 = x - x1 * 31623, y - y1 * 31623 return (x1 * y1 * 14122 + (x1 * y0 + x0 * y1) * 31623 + x0 * y0) % mod end local function badd(x, y) return (x + y) % mod end local function bsub(x, y) return x < y and x - y + mod or x - y end local function modpow(src, pow) local res = 1 while 0 < pow do if pow % 2 == 1 then res = bmul(res, src) pow = pow - 1 end src = bmul(src, src) pow = mfl(pow / 2) end return res end local function modinv(src) return modpow(src, mod - 2) end local fact = {1} local invs = {1} local invfact = {1} for i = 2, 100 do fact[i] = bmul(fact[i - 1], i) invs[i] = bmul(mfl(mod / i), mod - invs[mod % i]) invfact[i] = bmul(invfact[i - 1], invs[i]) end local function getComb(n, k) if k == 0 or k == n then return 1 end return bmul(fact[n], bmul(invfact[k], invfact[n - k])) end local p2 = {2} for i = 2, 100010 do p2[i] = (p2[i - 1] * 2) % mod end local function getp2(i) return i == 0 and 1 or p2[i] end local n = io.read("*n") local b = {} for i = 1, n do b[i] = io.read("*n") end local ret = 1 local cnt = 0 local prv = 0 for i = 1, n do cnt = cnt + 1 if 0 <= b[i] then local x = bor(prv, b[i]) if x ~= b[i] then print(0) os.exit() end local tp, tb = prv, b[i] local olditem = 0 local newitem = 0 for j = 1, 30 do if tp % 2 == 1 then olditem = olditem + 1 elseif tb % 2 == 1 then newitem = newitem + 1 end tp = mfl(tp / 2) tb = mfl(tb / 2) end local v = 0 for j = newitem, 0, -1 do local tmp = modpow(getp2(olditem + j) - 1, cnt) tmp = bmul(tmp, getComb(newitem, j)) if (newitem - j) % 2 == 0 then v = badd(v, tmp) else v = bsub(v, tmp) end end -- print(i, v) ret = bmul(ret, v) prv = b[i] cnt = 0 end end print(ret)