package main

import (
	"bufio"
	"fmt"
	"math"
	"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
}

var N, V int
var c []int
var b []int

func rec(n, v int) int {
	if v < 0 {
		return 0
	}
	if n == 1 {
		return c[0] * v
	}
	m := (v + n - 1) / n
	ret := math.MaxInt64 / 8
	for i := 0; i <= m; i++ {
		r := rec(n-1, v-i*n) + b[n]*i
		// out(n, b[n]*i, r)
		ret = min(ret, r)
	}
	return ret
}

func main() {
	sc.Split(bufio.ScanWords)
	N, V = getInt(), getInt()
	c = getInts(N)
	b = make([]int, N+1)
	for i := 1; i <= N; i++ {
		b[i] = b[i-1] + c[i-1]
	}
	sum := b[N]
	if V <= N {
		out(sum)
		return
	}

	out(rec(N, V-N) + sum)
	// v := V - N
	// ans := math.MaxInt64
	// out(v)
	// for i := 1; i <= N; i++ {
	// 	if v < i {
	// 		break
	// 	}
	// 	x := b[i]*(v/i) + b[v%i]
	// 	out(x, v/i, v%i, b[i], b[v%i], sum, sum+x)
	// 	ans = min(ans, sum+x)
	// }
	// out(ans)
}