local mmi, mma = math.min, math.max local mfl, mce = math.floor, math.ceil local bls, brs = bit.lshift, bit.rshift local Heapq = {} Heapq.create = function(self, lt) self.lt = lt self.cnt = 0 self.t = {} end Heapq.empty = function(self) return self.cnt == 0 end Heapq.push = function(self, v) local hqlt = self.lt local hqt = self.t local c = self.cnt + 1 self.cnt = c hqt[c] = v while 1 < c do local p = brs(c, 1) if hqlt(hqt[c], hqt[p]) then hqt[c], hqt[p] = hqt[p], hqt[c] c = p else break end end end Heapq.pop = function(self) local hqlt = self.lt local hqt = self.t local ret = hqt[1] local c = self.cnt hqt[1] = hqt[c] c = c - 1 self.cnt = c local p = 1 while true do local d1, d2 = p * 2, p * 2 + 1 if c < d1 then break elseif c < d2 then if hqlt(hqt[d1], hqt[p]) then hqt[d1], hqt[p] = hqt[p], hqt[d1] end break else if hqlt(hqt[d1], hqt[d2]) then if hqlt(hqt[d1], hqt[p]) then hqt[d1], hqt[p] = hqt[p], hqt[d1] p = d1 else break end else if hqlt(hqt[d2], hqt[p]) then hqt[d2], hqt[p] = hqt[p], hqt[d2] p = d2 else break end end end end return ret end Heapq.new = function(lt) local obj = {} setmetatable(obj, {__index = Heapq}) obj:create(lt) return obj end local n, m, p = io.read("*n", "*n", "*n") local a = {} local amax = 0 for i = 1, n do a[i] = io.read("*n") amax = mma(amax, a[i]) end if m < amax then print(1) os.exit() end local c = {} for i = 1, n do local ci = 1 local ai = a[i] while ai % p == 0 do ci = ci + 1 ai = mfl(ai / p) end if 1 < ai then if c[ai] then c[ai] = mmi(c[ai], ci) else c[ai] = ci end end end if not next(c) then print(-1) os.exit() end local cm = {} for k, v in pairs(c) do table.insert(cm, {k, v}) end table.sort(cm, function(a, b) return a[1] < b[1] end) local cn = #cm local val, score, valmap = {}, {}, {} local lim = mfl(m / amax) + 1 valmap[m] = 1 val[1] = 1 score[1] = 1 local hq = Heapq.new(function(a, b) return val[a] < val[b] end) hq:push(1) local ret = 1000000007 while not hq:empty() do local idx = hq:pop() local v, s = val[idx], score[idx] for i = 1, cn do local mul = cm[i][1] local cost = cm[i][2] if lim <= v * mul then ret = mmi(ret, s + cost) else local dst = v * mul local dstidx = valmap[dst] if dstidx then score[dstidx] = mmi(score[dstidx], s + cost) else table.insert(val, dst) table.insert(score, s + cost) valmap[dst] = #val hq:push(#val) end end end end print(ret) -- print(os.clock())