package main import ( "bufio" "fmt" "os" "sort" "strconv" ) func out(x ...interface{}) { fmt.Println(x...) } var sc = bufio.NewScanner(os.Stdin) func getInt() int { sc.Scan() i, e := strconv.Atoi(sc.Text()) if e != nil { panic(e) } return i } func getInts(N int) []int { ret := make([]int, N) for i := 0; i < N; i++ { ret[i] = getInt() } return ret } func getString() 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 } 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 } func main() { sc.Split(bufio.ScanWords) B, N := getInt(), getInt() c := getInts(N) l := -1 r := int(1e11) ans := int(1e15) for l+1 != r { m := (l + r) / 2 b := 0 cnt := 0 for i := 0; i < N; i++ { if m > c[i] { x := m - c[i] b -= x cnt += x } else if m < c[i] { x := c[i] - m b += x cnt += x } } if b+B >= 0 { ans = min(ans, cnt) } if b < 0 { r = m } else { l = m } } out(ans) }