Go: package main

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

//util
var sc = bufio.NewScanner(os.Stdin)

func nextStr() string {
	sc.Scan()
	return sc.Text()
}

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func printList(list []int) {
	buf := bufio.NewWriter(os.Stdout)
	for _, v := range list {
		buf.Write([]byte(fmt.Sprintf(" %d", v)))
	}
	buf.Write([]byte("\n"))
	buf.Flush()
}

//solve
//単純な場合
func matrixChainMultiplication() {
	//行列が1つだけのとき
	for i := 1; i <= n; i++ {
		m[i][i] = 0
	}
	for l := 2; l <= n; l++ {
		for i := 1; i <= n-l+1; i++ {
			j := i + l - 1
			m[i][j] = 1 << 21
			//kまでで区切る
			for k := i; k <= j-1; k++ {
				m[i][j] = min(m[i][j], m[i][k]+m[k+1][j]+p[i-1]*p[k]*p[j])
			}
		}
	}
}

func max(a, b int) int {
	if a > b {
		return a
	} else {
		return b
	}
}

func min(a, b int) int {
	if a > b {
		return b
	} else {
		return a
	}
}

const MAX = 100

var n int
var p [MAX + 1]int

//m[i][j]: Mi * Mi+1 * ... * Mjを計算するときに必要なスカラー乗算の最小回数
var m [MAX + 1][MAX + 1]int

func main() {
	sc.Split(bufio.ScanWords)
	n = nextInt()
	for i := 1; i <= n; i++ {

		p[i-1] = nextInt() //行数
		p[i] = nextInt()   //列数
	}

	matrixChainMultiplication()
	fmt.Println(m[1][n])
}

Python: # -*- coding: utf-8 -*-
N = int(input())
p = [0 for _ in range(N+1)]

p[0], p[1] = map(int, input().split())
for n in range(2, N+1):
    p[n] = list(map(int, input().split()))[1]

M = [[0]*(N+1) for _ in range(N+1)]

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

for l in range(2, N+1):
    for i in range(1, N-l+2):
        j = i + l - 1
        M[i][j] = float("inf")
        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: # https://onlinejudge.u-aizu.ac.jp/courses/lesson/1/ALDS1/10/ALDS1_10_B
# 普通に難しい
# アイデアは写真の解説を参照

# データの入力
N = int(input())

for i in range(N):
    if i == 0:
        P = list(map(int, input().split()))
        continue
    P.append(int(input().split()[1]))

# dpテーブルの用意 minを取るときはinf埋めしておくと処理が楽になるしバグが見つかりやすい
INF = 2**32-1
dp = [[INF]*N for _ in range(N)]

# dpテーブルの初期化
# 対角成分0
for ij in range(N):
    dp[ij][ij] = 0

# dpの更新 どう更新しているのか、なんでこう更新するのかは写真を参照
for l in range(1, N):  # lは対角成分からいくつ離れているか (なん個行列をかけるかという解釈も可)
    for i in range(N):
        j = i+l
        if j >= N:
            continue
        for k in range(i, j):  # 最小値探索
            dp[i][j] = min(dp[i][k] + dp[k+1][j] +
                           P[i] * P[k+1] * P[j+1], dp[i][j])
print(dp[0][-1])

Python: import sys
def input():
    return sys.stdin.readline()[:-1]
n = int(input())
A = [list(map(int, input().split())) for _ in range(n)]

p = [A[0][0]] + [A[i][1] for i in range(n)]
m = [[0 for i in range(n+1)] for j in range(n+1)]

for l in range(2,n+1):
    for i in range(1,n-l+1+1):
        j = i + l - 1
        for k in range(i,j):
            x = m[i][k] + m[k+1][j] + p[i-1]*p[k]*p[j]
            if not 0<m[i][j]<=x:
                m[i][j] = x
print(m[1][n])

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

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

logging.basicConfig(level=logging.DEBUG, format="DBG: %(message)s")

def dbg(msg, *args, **kwargs):
    logging.debug(msg, *args, **kwargs)

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

import sys


def mat_mul_opt(_mat_info):
    r, c = map(int, _mat_info[0])
    rc_info.extend([r, c])
    for each in _mat_info[1:]:
        rc_info.append(int(each[1]))

    for l in range(2, mat_num + 1):
        for i in range(1, mat_num - l + 2):
            j = i + l - 1
            ans[i][j] = 1e7
            for k in range(i, j):
                ans[i][j] = min(ans[i][j], ans[i][k] + ans[k + 1][j] +
                                rc_info[i - 1] * rc_info[k] * rc_info[j])

    return ans[1][mat_num]


if __name__ == '__main__':
    _input = sys.stdin.readlines()
    mat_num = int(_input[0])
    mat_info = tuple(map(lambda x: x.split(), _input[1:]))

    rc_info = []
    ans = [[0] * (mat_num + 1) for _ in range(mat_num + 1)]
    print(mat_mul_opt(mat_info))

Python: n = int(input())
p = [None] * (n+1)# i番目の列数 = i+1番目の行数
for i in range(n):
  p[i], p[i+1] = map(int, input().split())

INF = 10**18
m = [[None] * n for _ in range(n)]
for i in range(n):
  m[i][i] = 0
  
for l in range(2,n+1):# 行列の連鎖数
  for i in range(n-l+1):
    j = i + l - 1# [i, j]の範囲の計算の最小コストを考える
    m[i][j] = INF
    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[0][n-1])

Python: n = int(input())
p = []
a, b = map(int, input().split())
p.append(a)
p.append(b)
for _ in range(n-1):
    a, b = map(int, input().split())
    p.append(b)

m = [[0]*(n+1) for _ in range(n+1)]
for l in range(1, n):
    for i in range(1, n-l+1):
        j = i+l
        m[i][j] = float('inf')
        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

n = int(sys.stdin.readline().strip())

p = [0]*(n+1)
dp = [[0]*(n+1) for _ in range(n+1)]

for i in range(n):
    p[i], p[i+1] = map(int, sys.stdin.readline().strip().split())

# dpテーブルの対角成分を初期値とし、右斜に更新していく
# 利用する行列の数
for l in range(2, n+1):
    # 利用する範囲（l個の行列のうちi - jの範囲の行列を扱う）
    for i in range(1, n-l+2):
        j = i + l - 1
        dp[i][j] = float("inf")
        # 掛け合わせの区切り位置
        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])

print(dp[1][n])

Python: n = int(input())
size = [int(i) for i in input().split()]
for _ in range(n - 1):
    _, a = map(int, input().split())
    size.append(a)
dp = [[0] * (n) for _ in range(n)]
# init
for i in range(n):
    dp[i][i] = 0
# solve
for l in range(1, n):
    for i in range(n - l):
        j = i + l
        min = 10 ** 9
        for k in range(i, j):
            tmp = dp[i][k] + dp[k + 1][j] + size[i] * size[k + 1] * size[j + 1]
            if tmp < min:
                min = tmp
        dp[i][j] = min
print(dp[0][-1])