package main import ( "bufio" "fmt" "math" "os" "sort" "strconv" ) var sc = bufio.NewScanner(os.Stdin) var wr = bufio.NewWriter(os.Stdout) func out(x ...interface{}) { fmt.Fprintln(wr, x...) } func getI() int { sc.Scan() i, e := strconv.Atoi(sc.Text()) if e != nil { panic(e) } return i } func getF() float64 { sc.Scan() i, e := strconv.ParseFloat(sc.Text(), 64) if e != nil { panic(e) } return i } func getInts(N int) []int { ret := make([]int, N) for i := 0; i < N; i++ { ret[i] = getI() } return ret } func getS() string { sc.Scan() return sc.Text() } // min, max, asub, absなど基本関数 func max(a, b int) int { if a > b { return a } return b } func min(a, b int) int { if a < b { return a } return b } // min for n entry func nmin(a ...int) int { ret := a[0] for _, e := range a { ret = min(ret, e) } return ret } // max for n entry func nmax(a ...int) int { ret := a[0] for _, e := range a { ret = max(ret, e) } return ret } func asub(a, b int) int { if a > b { return a - b } return b - a } func abs(a int) int { if a >= 0 { return a } return -a } func lowerBound(a []int, x int) int { idx := sort.Search(len(a), func(i int) bool { return a[i] >= x }) return idx } func upperBound(a []int, x int) int { idx := sort.Search(len(a), func(i int) bool { return a[i] > x }) return idx } type BIT struct { v []int } func newBIT(n int) *BIT { b := new(BIT) b.v = make([]int, n) return b } func (b BIT) sum(a int) int { ret := 0 for i := a + 1; i > 0; i -= i & -i { ret += b.v[i-1] } return ret } func (b BIT) rangeSum(x, y int) int { if y == 0 { return 0 } y-- if x == 0 { return b.sum(y) } else { return b.sum(y) - b.sum(x-1) } } func (b BIT) add(a, w int) { n := len(b.v) for i := a + 1; i <= n; i += i & -i { b.v[i-1] += w } } func main() { defer wr.Flush() sc.Split(bufio.ScanWords) sc.Buffer([]byte{}, math.MaxInt32) // this template is new version. // use getI(), getS(), getInts(), getF() N := getI() a := getInts(N) b := getInts(N) sort.Ints(a) m := make(map[int]int) for i := 0; i < N; i++ { m[a[i]] = 1 m[b[i]] = 1 } x := make([]int, 0, len(m)) for e := range m { x = append(x, e) } sort.Ints(x) for i := 0; i < len(x); i++ { m[x[i]] = i + 1 } bit := newBIT(len(x) + 10) ans := 0 for i := 0; i < N; i++ { x := m[b[i]] y := m[a[i]] bit.add(x, 1) ans += bit.sum(y - 1) } out(ans) }