Go: package main

import (
	"bufio"
	"fmt"
	"io"
	"math"
	"os"
	"strconv"
)

const (
	initialBufSize = 100000
	maxBufSize     = 1000000
)

var sc *bufio.Scanner

func initScanner(r io.Reader) *bufio.Scanner {
	buf := make([]byte, initialBufSize)

	sc := bufio.NewScanner(r)
	sc.Buffer(buf, maxBufSize)
	sc.Split(bufio.ScanWords) // bufio.ScanLines
	return sc
}

func main() {
	sc = initScanner(os.Stdin)
	fmt.Println(resolve(parseProblem()))
}

type matrixSize struct{ row, col int }

func calcNum(i, j matrixSize) int {
	return i.row * j.col * i.col
}

func parseProblem() (int, []matrixSize) {
	n := scanInt(sc)
	sizes := make([]matrixSize, n)
	for i := 0; i < n; i++ {
		sizes[i] = matrixSize{row: scanInt(sc), col: scanInt(sc)}
	}
	return n, sizes
}

var dp [][]int

func initDP(n int) {
	dp = make([][]int, n+1)
	for i := 0; i < len(dp); i++ {
		dp[i] = make([]int, n+1)
		for j := 0; j < len(dp[i]); j++ {
			dp[i][j] = math.MaxInt64
		}
	}
}

func resolve(n int, sizes []matrixSize) int {
	// TODO 復習
	initDP(n)
	_rec(sizes, 0, n)
	return dp[0][n]
}

func _rec(sizes []matrixSize, l, r int) int {
	if dp[l][r] != math.MaxInt64 {
		return dp[l][r]
	}
	if r-l <= 1 {
		dp[l][r] = 0
		return 0
	}
	num := math.MaxInt64
	for i := l + 1; i < r; i++ {
		v := _rec(sizes, l, i) + _rec(sizes, i, r) + calcNum(matrixSize{sizes[l].row, sizes[i].row}, matrixSize{sizes[i].row, sizes[r-1].col})
		if v < num {
			num = v
		}
	}
	dp[l][r] = num
	return dp[l][r]
}

// snip-scan-funcs
func scanInt(sc *bufio.Scanner) int {
	sc.Scan()
	i, _ := strconv.Atoi(sc.Text())
	return int(i)
}
func scanString(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

Python: import sys


class Mat(object):

  def __init__(self, row, col):
    self.row = row
    self.col = col
    
def get_min_mult_cnt_dp(i, j, mat_list):

  multp = [[sys.maxsize for i in range(len(mat_list))] for i in range(len(mat_list))]

  

  # 長さ0連鎖の演算量
  for i in range(len(mat_list)):
    multp[i][i] = 0

  for le in range(1, len(mat_list)):
    for i in range(len(mat_list)-le):
      j = i + le

      tmp = sys.maxsize
      for k in range(i, j):
        p = mat_list[i].row
        n = mat_list[k].col
        q = mat_list[j].col
        tmp = multp[i][k] + multp[k+1][j] + p*n*q

        if (tmp < multp[i][j]):
          multp[i][j] = tmp
    
  
  return multp[i][j]
mat_list = []
num = int(input())
for i in range(num):
    a,b = map(int,input().split())
    mat_list.append(Mat(a,b))



print(int(get_min_mult_cnt_dp(0, num-1, mat_list)))

Python: import sys
read = sys.stdin.read
readline = sys.stdin.buffer.readline
sys.setrecursionlimit(10 ** 8)
INF = float('inf')
MOD = 10 ** 9 + 7

def matrixChainMultiplication(n,p):
    dp = [[0]*(n+1) for _ in range(n + 1)]
    for l in range(2, n + 1):
        for i in range(1, n - l + 2):
            j = i + l - 1
            dp[i][j] = INF
            for k in range(i, j):
                dp[i][j] = min(dp[i][j], dp[i][k] + dp[k + 1][j] + p[i - 1] * p[k] * p[j])
    return dp[1][n]


def main():
    N = int(readline())
    P = []

    for _ in range(N):
        r, c = map(int, readline().split())
        P.append(r)
    P.append(c)

    print(matrixChainMultiplication(N,P))

    


if __name__ == '__main__':
    main()

Python: if __name__ == '__main__':
    from sys import stdin
    input = stdin.readline

    N = 100
    p = [0]*(N+1)
    m = [[0]*(N+1) for _ in range(N+1)]

    n = int(input())
    for i in range(n):
        p[i], p[i+1] = map(int, input().split())

    for l in range(2, n+1):
        for i in range(1, n-l+2):
            j = i + l - 1
            m[i][j] = 2**21 # 十分大きい数
            for k in range(i, j):
                m[i][j] = min(m[i][j], m[i][k]+m[k+1][j]+p[i-1]*p[k]*p[j])

    print(m[1][n])

Python: import sys

def get_min_cost(n, p):
	m = [[0 for x in range(n+1)] for x in range(n+1)]
	for s in range(n):
		i = 1
		for j in range(s+2, n):
			m[i][j] = sys.maxsize
			for k in range(i, j+1):
				m[i][j] = min(m[i][j], m[i][k]+m[k+1][j]+p[i-1]*p[k]*p[j])
			i+=1	
	return m[1][n]

n = int(input())
p = [0] * (n+1)
j = 0
for i in range(n):
	a = list(map(int, input().split()))
	if i == 0:
		p[j] = a[0]
		j += 1
	p[j] = a[1]
	j += 1
print(get_min_cost(n, p))

Python: n = int(input())

M = []
for i in range(n):
    r, c = map(int, input().split())
    if i == 0: M.append(r)
    M.append(c)

dp = [[float("inf")] * (n+1) for _ in range(n+1)]

for i in range(1,n+1):
    dp[i][i] = 0

for l in range(2, n+1):
    for i in range(1,n-l+2):
        j = i + l -1
        for k in range(i, j):
            dp[i][j] = min(dp[i][j], dp[i][k] + dp[k+1][j] + M[i-1]*M[k]*M[j])

print(dp[1][n])

Python: def s():
 n=int(input())+1
 e=[input().split()for _  in[0]*~-n]
 p=[int(e[0][0])]+list(int(x[1])for x in e)
 m=[[0]*n for _ in[0]*n]
 for i in range(n):
  for r in range(n-i-1):
   c=r+i+1
   for j in range(r+1,c):
    x=m[r][j]+m[j][c]+p[r]*p[j]*p[c]
    if not 0<m[r][c]<x:m[r][c]=x
 print(m[r][c])
if'__main__'==__name__:s()

Python: import sys
input = sys.stdin.readline
n = int(input())
p0, p1 = map(int, input().split())
p = [p0, p1]
for _ in range(1, n):
    _, tmp = map(int, input().split())
    p.append(tmp)
# M[i]: p[i-1] * p[i]size

dp = [[0]*(n+1) for _ in range(n+1)]
#dp[i][j]: M[i]...M[j] の掛け算最小回数

for i in range(0, n+1):
    dp[i][i] = 0
# for i in range(1, n+1):
#     for j in range(i+1, n+1):
#         for k in range(i, j):
#             # M[i]...M[k], M[k+1]...M[j]
#             dp[i][j] = min(dp[i][j], dp[i][k] + dp[k+1][j] + p[i-1]*p[k]*p[j])
# print(dp[1][n])

for w in range(2, n+1):
    for i in range(1, n+1):
        j = i+w-1
        if j >= n+1:
            continue
        res = 1e30
        for k in range(i, j):
            res = min(
                res,
                dp[i][k] + dp[k+1][j] + p[i-1] * p[k] * p[j]
            )
        dp[i][j] = res
print(dp[1][n])

Python: #!/usr/bin/env python3
# -*- coding: utf-8 -*-

import sys
import re
import math
import collections
import itertools
import functools

def dbg(*args):
    print("DBG: ", file=sys.stderr, end="")
    print(*args, file=sys.stderr)

Mat = collections.namedtuple("Mat", "r c")

def mat_mul(ms):
    return Mat(ms[0].r, ms[-1].c)

def cost(m1, m2):
    return m1.r * m1.c * m2.c

def solve(n, ms):
    if n == 1: return 0

    dp = {}
    for i in range(n):
        dp[(i,i)] = 0

    for l in range(2, n+1):
        for i in range(n-l+1):
            cost_min = math.inf
            #cost_min = float("inf")
            for j in range(l-1):
                dbg("l, i, j: %d %d %d", l, i, j)
                m_lhs = mat_mul(ms[i:i+j+1])
                m_rhs = mat_mul(ms[i+j+1:i+l])
                #dbg("m_lhs, m_rhs: %r %r", m_lhs, m_rhs)
                cost_lhs = dp[(i,i+j)]
                cost_rhs = dp[(i+j+1,i+l-1)]
                #dbg("cost_lhs, cost_rhs: %d %d", cost_lhs, cost_rhs)
                cost_mul = cost(m_lhs, m_rhs)
                #dbg("cost_mul: %d", cost_mul)
                cost_now = cost_mul + cost_lhs + cost_rhs
                #dbg("cost_now: %d", cost_now)
                if cost_min > cost_now:
                    cost_min = cost_now
            dp[(i,i+l-1)] = cost_min

    #dbg(dp)
    return dp[(0,n-1)]

def main():
    n = int(input())

    ms = []
    for _ in range(n):
        r,c = map(int, input().split())
        ms.append(Mat(r,c))

    print(solve(n, ms))

if __name__ == "__main__": main()

Python: # 連鎖行列積 Matrix chain multiplication

n = int(input())
p = [-1 for i in range(n + 1)]
M = [[-1 for i in range(n + 1)] for i in range(n + 1)]

for i in range(1, n + 1):
    l, m = (int(i) for i in input().split())
    p[i - 1] = l
    p[i] = m

for i in range(1, n + 1):
    M[i][i] = 0

for l in range(2, n + 1):
    for i in range(1, n - l + 2):
        j = i + l - 1
        M[i][j] = 2000000000
        for k in range(i, j):
            M[i][j] = min(M[i][j], M[i][k] + M[k + 1][j] + p[i - 1] * p[k] * p[j])

print(M[1][n])