Go: package main

/*
連鎖行列積
*/

import (
	"bufio"
	"bytes"
	"fmt"
	"log"
	"math"
	"os"
	"strconv"
	"strings"
)

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

type mem *[][]int

func main() {
	scanner := makeScanner(1024)
	n := eGetInt(scanner)
	p := make([]int, n+1)
	for i := 0; i < n; i++ {
		rowcol := eGetInts(scanner)
		p[i] = rowcol[0]
		p[i+1] = rowcol[1]
	}
	m := make([][]int, n)
	for i := 0; i < n; i++ {
		m[i] = make([]int, n)
	}
	// 初期値の格納
	for i := 0; i < n; i++ {
		for j := i; j < n; j++ {
			if i == j {
				m[i][j] = 0 //  同じ行列へのコストは当然0
			} else {
				m[i][j] = math.MaxInt64
			}
		}
	}

	// num : 行列の数. num == 1の場合は初期値0を格納ずみ
	for num := 2; num <= n; num++ {
		// s : スタート行列番号
		for s := 0; s+num <= n; s++ {
			// t : 終了行列番号
			t := s + num - 1
			// k : 仕切
			for k := s; k < t; k++ {
				m[s][t] = min(m[s][t], m[s][k]+m[k+1][t]+p[s]*p[k+1]*p[t+1])
			}
		}
	}
	fmt.Println(m[0][n-1])
}

////////////////////////////////////////////////////////////////////////////////
// ライブラリ
////////////////////////////////////////////////////////////////////////////////
func makeScanner(maxByte int) *bufio.Scanner {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Buffer(make([]uint8, 0, 8192), maxByte)
	return scanner
}
func makeWordScanner() *bufio.Scanner {
	scanner := makeScanner(8192)
	scanner.Split(bufio.ScanWords)
	return scanner
}
func eGetLine(r *bufio.Scanner) string {
	if r.Scan() {
		return r.Text()
	}
	err := r.Err()
	if err != nil {
		log.Fatal(err)
	}
	// EOF
	return ""
}
func eGetInt(r *bufio.Scanner) int {
	line := eGetLine(r)
	return eAtoi(line)
}
func eGetFields(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Fields(line)
}
func eGetInts(r *bufio.Scanner) []int {
	fields := eGetFields(r)
	ints := make([]int, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoi(fields[i])
	}
	return ints
}
func eGetChars(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Split(line, "")
}
func eAtoi(s string) int {
	n, err := strconv.Atoi(s)
	if err != nil {
		log.Fatal(err)
	}
	return n
}

type ints []int

func (s ints) String() string {
	var buf bytes.Buffer
	buf.WriteString("[")
	sep := ""
	for _, v := range s {
		buf.WriteString(fmt.Sprintf("%s%d", sep, v))
		sep = ", "
	}
	buf.WriteString("]")
	return buf.String()
}

func reverse(a ints) ints {
	r := make(ints, len(a))
	for i := 0; i < len(a); i++ {
		r[i] = a[len(a)-1-i]
	}
	return r
}
func max(a ints) (int, bool) {
	if len(a) == 0 {
		return 0, false
	}
	m := a[0]
	for _, e := range a {
		if e > m {
			m = e
		}
	}
	return m, true
}

// func min(a []int) int {
// 	m := a[0]
// 	for _, v := range a {
// 		if v < m {
// 			m = v
// 		}
// 	}
// 	return m
// }

func sum(a ints) int {
	if len(a) == 0 {
		return 0
	}
	sum := 0
	for _, e := range a {
		sum += e
	}
	return sum
}
func find(n int, a ints) int {
	for i, v := range a {
		if n == v {
			return i
		}
	}
	return -1
}

C++: #include <bits/stdc++.h>
using namespace std;

int	main()
{
	int	cnt[100][100];
	int	n;
	cin >> n;
	for (int i = 0; i < n; ++i) {
		for (int j = 0; j < n; ++j)
			cnt[i][j] = -1;
		cnt[i][i] = 0;
	}
	vector<int>	r_vec(n), c_vec(n);
	for (int i = 0; i < n; ++i)
		cin >> r_vec.at(i) >> c_vec.at(i);
	for (int i = 1; i < n; ++i) {
		int	k;
		for (int j = 0; (k = i + j) < n; ++j) {
			for (int l = j; l < k; ++l) {
				int	tmp_cnt = cnt[j][l] + cnt[l + 1][k];
				tmp_cnt += r_vec.at(j) * c_vec.at(l) * c_vec.at(k);
				if (cnt[j][k] == -1 || cnt[j][k] > tmp_cnt)
					cnt[j][k] = tmp_cnt;
			}
		}
	}
	cout << cnt[0][n - 1] << endl;
}

C++: #include<cstdio>
#include<algorithm>
using namespace std;
static const int N=100;
int main(){
  int n,p[N+1],m[N+1][N+1];
  scanf("%d",n);;
  for(int i=1;i<=n;i++)
    cin >> p[i-1] >> p[i];
  for(int i=1;i<=n;i++)m[i][i]=0;
  for(int l=2;l<=n;l++){
    for(int i=1;i<=n-1+1;i++){
      int j=i+l-1;
      m[i][j]=(1<<21);
      for(int 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]);
      }
    }
  }
  printf("%d\n",m[1][n]);
  return 0;
}

C++: #include "bits/stdc++.h"

using namespace std;

using ll = long long;
using ld = long double;
using P = pair<string, int>;
constexpr ld EPS = 1e-12;
constexpr int INF = numeric_limits<int>::max() / 2;
constexpr int MOD = 1e9 + 7;

template <typename T>
void printv(const vector<T> &v)
{
    int sz = v.size();
    for (int i = 0; i < sz; i++)
    {
        cout << v[i] << " \n"[i == sz - 1];
    }
}

int n;
vector<ll> r(100), c(100);
ll dp[100][100];

// dp[l][r]
ll calc(int lx, int rx)
{
    if (dp[lx][rx] != 1e15)
    {
        return dp[lx][rx];
    }
    for (int i = lx; i < rx; i++)
    {
        dp[lx][rx] = min(dp[lx][rx], calc(lx, i) + calc(i + 1, rx) + r[lx] * c[i] * c[rx]);
    }
    return dp[lx][rx];
}

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);

    cin >> n;
    for (int i = 0; i < n; i++)
        cin >> r[i] >> c[i];
    for (int i = 0; i < n; i++)
    {
        dp[i][i] = 0;
        for (int j = i + 1; j < n; j++)
        {
            dp[i][j] = 1e15;
        }
    }
    cout << calc(0, n - 1) << endl;
}

C++: #include <iostream>
#include <algorithm>
using namespace std;

int main()
{
	int n;
	int v[101];
	long m[100][100];
	const long nil = 999999999;

	cin >> n;

	for (int i = 0; i < n; i++)
		cin >> v[i] >> v[i + 1];

	for (int i = 0; i < 100; i++)
		for (int j = 0; j < 100; j++)
			if (i == j)
				m[i][j] = 0;
			else
				m[i][j] = nil;
	
	for(int i = n - 2; i > -1; i--)
		for(int j = i + 1; j < n; j++)
			for (int k = i; k < n; k++)
				m[i][j] = min(m[i][j], m[i][k] + m[k + 1][j] + v[i] * v[k + 1] * v[j + 1]);

	cout << m[0][n - 1] << endl;

	return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
typedef long long int ll;

struct mat {
	ll l, c, r;
};

int main() {
	ios::sync_with_stdio(false); cin.tie(0);

	mat a[110][110];
	int N; cin >> N;
	ll l, r;
	for (int i = 0; i < N; i++) {
		cin >> l >> r;
		a[i][i].l = l;
		a[i][i].r = r;
		a[i][i].c = 0;
	}
	for (int l = 1; l < N;l++) {
		for (int i = 0; i+l < N; i++) {
			ll m = 1000010;
			a[i][i + l].l = a[i][i].l;
			a[i][i + l].r = a[i + l][i + l].r;
			for (int j = i; j < i + l; j++) {
				m = min(a[i][j].l * a[i][j].r * a[j + 1][i + l].r + a[i][j].c + a[j + 1][i + l].c, m);
			}
			a[i][i + l].c = m;
		}
	}
	cout << a[0][N-1].c << endl;
}

C++: #include <iostream>
#include <algorithm>
#include <vector>
using namespace std;

static const int N = 1000;

int main()
{
    int n, p[N + 1];
    vector<vector<int>> m(N + 1, vector<int>(N + 1));
    cin >> n;
    for (int i = 1; i <= n; i++)
    {
        cin >> p[i - 1] >> p[i];
    }
    for (int i = 1; i <= n; i++)
    {
        m.at(i).at(i) = 0;
    }
    for (int l = 2; l <= n; l++)
    {
        for (int i = 1; i <= n - 1; i++)
        {
            int j = i + l - 1;
            m.at(i).at(j) = (1 << 21);
            for (int k = i; k <= j - 1; k++)
            {
                m.at(i).at(j) = min(m.at(i).at(j), m.at(i).at(k) + m.at(k+1).at(j) + p[i - 1] * p[k] * p[j]);
            }
        }
    }
    cout << m[1][n] << endl;
    return 0;
}