Go: package main

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

type Matrix struct {
	r int // num of row
	c int // num of column
}

type Range struct {
	start int // index, inclusive
	end   int // index, inclusive
}

func calcMultiplication(x, y Matrix) (Matrix, int) {
	if x.c != y.r {
		panic("cannnot calculate")
	}
	return Matrix{x.r, y.c}, x.r * y.c * x.c
}

func calcMinMatrixChainMultiplication(matrices []Matrix, r Range, memo map[Range]int) (Matrix, int) {
	if v, ok := memo[r]; ok {
		return Matrix{matrices[0].r, matrices[len(matrices)-1].c}, v
	}
	if len(matrices) == 0 {
		panic("must not be empty")
	} else if len(matrices) == 1 {
		return matrices[0], 0
	}

	var minCount int = math.MaxInt32

	for i := 0; i < len(matrices)-1; i++ {
		formerMatrices := matrices[:i+1]
		latterMatrices := matrices[i+1:]
		matF, countF := calcMinMatrixChainMultiplication(formerMatrices, Range{0, i}, memo)
		matL, countL := calcMinMatrixChainMultiplication(latterMatrices, Range{i + 1, len(matrices) - 1}, memo)
		_, countFL := calcMultiplication(matF, matL)
		count := countF + countL + countFL
		if count < minCount {
			minCount = count
		}
	}
	memo[r] = minCount
	return Matrix{matrices[0].r, matrices[len(matrices)-1].c}, minCount
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	n, _ := nextInt(sc)
	matrices := make([]Matrix, n)
	for i := 0; i < n; i++ {
		r, _ := nextInt(sc)
		c, _ := nextInt(sc)
		matrices[i] = Matrix{r, c}
	}
	memo := make(map[Range]int)
	_, resultCount := calcMinMatrixChainMultiplication(matrices, Range{0, len(matrices) - 1}, memo)
	fmt.Println(resultCount)
}

func nextInt(sc *bufio.Scanner) (int, error) {
	sc.Scan()
	return strconv.Atoi(sc.Text())
}

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

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

DEBUG = True
DEBUG = False

def dbg(*args):
    if DEBUG:
        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: import sys
n = int(input())
input_list = [[int(i) for i in str.split()] for str in sys.stdin.read().splitlines()]
size_list = [0 for i in range(n+1)]
size_list[0] = input_list[0][0]
for i in range(1,n+1):
    size_list[i] = input_list[i-1][1]


m = [[float('inf') for i in range(n)] for j in range(n)]

for i in range(n):
    m[i][i] = 0

for x in range(n):
    i, j = 0, x
    for y in range(n-x):
        for k in range(i, j):
            m[i][j] = min(m[i][j], m[i][k] + m[k+1][j] + size_list[i]*size_list[k+1]*size_list[j+1])
        i, j = i+1, j+1

print(m[0][-1])

Python: N = int(input())
R = [0]*N
C = [0]*N
for i in range(N):
    R[i], C[i] = map(int, input().split())

INF = 10**18
dp = [[INF]*N for i in range(N)]
for i in range(N):
    dp[i][i] = 0
for l in range(1, N):
    for i in range(N-l):
        a0 = R[i]
        c0 = C[i+l]
        dp[i][i+l] = min(a0*C[j]*c0 + dp[i][j] + dp[j+1][i+l] for j in range(i, i+l))
print(dp[0][N-1])

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: INFTY = 100 * 100 * 100 + 1  # 1 ≤ r,c ≤ 100


n = int(input())

p = [None for _ in range(n + 1)]
m = [[None] * (n + 1) for _ in range(n + 1)]

for i in range(n):
    r, c = map(int, input().split())

    if i == 0:
        p[0] = r

    p[i + 1] = c

def matrix_chain_multiplication():
    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 + 1 + 1):
            j = i + l - 1
            m[i][j] = INFTY
            for k in range(i, j - 1 + 1):
                m[i][j] = min(m[i][j], m[i][k] + m[k + 1][j] + p[i - 1] * p[k] * p[j])


matrix_chain_multiplication()
print(m[1][n])

Python: def main():
    n=int(input())
    lst=tuple(tuple(map(int,input().split())) for _ in range(n))

    dp=[[0]*n for _ in range(n)]
    for i in range(1,n):
        for j in range(0,n-i):
            dp[j][j+i]=dp[j+1][j+i]+lst[j][0]*lst[j][1]*lst[j+i][1]
            for k in range(1,i):
                nwork=dp[j][j+k]+dp[j+k+1][j+i]+lst[j][0]*lst[j+k][1]*lst[j+i][1]
                if dp[j][j+i]>nwork : dp[j][j+i]=nwork
    
    print(dp[0][n-1])

main()

Python: n = int(input())
c = [0]*(n+1)
c[0], c[1] = map(int, input().split())
for i in range(2, n+1):
    c[i] = int(input().split()[1])

dp = [[10**7]*(n+1) for i in range(n+1)]  # dp[i][j] <- M_i~M_j

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

for l in range(2, n+1):  # l=j-i+1(length of chain)
    for i in range(1, n-l+2):
        j = i+l-1
        for k in range(i, j):  # kirutokoro
            dp[i][j] = min(dp[i][j], dp[i][k] + dp[k+1][j] + c[i-1]*c[k]*c[j])

print(dp[1][n])

Python: n = int(input())
RC = [list(map(int, input().split())) for _ in range(n)]
R = [RC[i][0] for i in range(n)]
C = [RC[i][1] for i in range(n)]

#n = 6
#R = [30, 35, 15, 5, 10, 20]
#C = [35, 15, 5, 10, 20, 25]

m = [[10**18]*(n+1) for _ in range(n+1)]
for i in range(n+1):
    m[i][i] = 0
    
for l in range(1, n):
    for i in range(1, n+1-l):
        m[i][i+l] = min([m[i][j] + m[j+1][i+l] + R[i-1]*C[j-1]*C[i+l-1] for j in range(i, i+l)])
        #print(i, i+l)
print(m[1][n])

Python: import sys
import itertools
# import numpy as np
import time
import math
import heapq
 
sys.setrecursionlimit(10 ** 7)
 
from collections import defaultdict
 
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
INF = 10 ** 9 + 7

# map(int, input().split())
# list(map(int, input().split()))

N = int(input())
M = [0] * N
for i in range(N):
    M[i] = tuple(map(int, input().split()))

dp = [[INF] * (N) for _ in range(N)]
for i in range(N):
    dp[i][i] = 0

def rec(l, r):
    if dp[l][r] != INF:
        return dp[l][r]
    res = INF
    for mid in range(l, r):
        res = min(res, rec(l, mid) + rec(mid + 1, r) + M[l][0] * M[mid][1] * M[r][1])
    dp[l][r] = res
    return res
print(rec(0, N - 1))