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;
#define INF 1000000000
#define mp make_pair
#define fi first
#define se second

int main()
{
    int n;cin >> n;
    vector<pair<int,int>> matrix(n);
    int a,b;
    for (int i=0;i<n;i++)
    {
        cin >> a >> b;
        matrix[i]=mp(a,b);
    }
    vector<vector<pair<int,pair<int,int>>>> dp(n,vector<pair<int,pair<int,int>>> (n,mp(INF,mp(-1,-1))));
    for (int i=0;i<n;i++)
    {
        dp[i][i].fi=0;
        dp[i][i].se.fi=matrix[i].fi;
        dp[i][i].se.se=matrix[i].se;
    }
    for (int len=1;len<n;len++)
    {
        for (int l=0;l<n-len;l++)
        {
            int r=l+len;
            //cout << l << r << endl;
            for (int m=l;m<r;m++)
            {
                if (dp[l][r].fi>dp[l][m].fi+dp[m+1][r].fi+dp[l][m].se.fi*dp[l][m].se.se*dp[m+1][r].se.se)
                {
                    //cout << l <<" " << r << ":" ;
                    dp[l][r].fi=dp[l][m].fi+dp[m+1][r].fi+dp[l][m].se.fi*dp[l][m].se.se*dp[m+1][r].se.se;
                    dp[l][r].se.fi=dp[l][m].se.fi;
                    dp[l][r].se.se=dp[m+1][r].se.se;
                    //cout << dp[l][r].fi<< endl;
                }
            }
        }
    }
    cout << dp[0][n-1].fi << endl;
    return 0;
}

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

constexpr int INF = 1e9;

int dp[110][110];

int main(){
  int n; cin >> n;
  int p[110];
  for( int i = 0; i < n; i++ ) cin >> p[i] >> p[i + 1];
  for( int i = 0; i < 110; i++ ){
    for( int j = 0; j < 110; j++ ){
      if( i != j ) dp[i][j] = INF;
    }
  }
  
  for( int l = 2; l <= n; l++ ){
    for( int i = 0; i < n - l + 1; i++ ){
      int j = l + i - 1;
      for( int k = i; k < j; k++ ){
	dp[i][j] = min( dp[i][j], dp[i][k] + dp[k + 1][j] + p[i] * p[k + 1] * p[j + 1] );
      }
    }
  }

  cout << dp[0][n - 1] << endl;
}

C++: #include<iostream>
#include<algorithm>
using namespace std;
#define INF 1<<30

static const int N = 100;

int main() {
    int n;
    int p[N+1], m[N+1][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[i][i] = 0;
    }
    for (int l=2; l<=n; l++) {
        for (int i=1; i<=n-l+1; i++) {
            int j = i+l-1;
            m[i][j] = INF;
            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]);
            }
        }
    }

    cout << m[1][n] << endl;
    return 0;
}

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

static const int N = 100;

int main() {
  int n, p[N+1], m[N+1][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[i][i] = 0;
  for (int l = 2; l <= n; l++) {
    for (int i = 1; i <= n-l+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]);
      }
    }
  }

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

  return 0;
}

C++: #include<iostream>
#include<algorithm>
using namespace std;
#define N 100
int main() {
	int n, p[N + 1], m[N + 1][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[i][i] = 0;
	for (int l = 2; l <= n; l++) {
		for (int i = 1; i <= n - l + 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[i][k] + m[k + 1][j] + p[i - 1] * p[k] * p[j]);
			}
		}
	}
	cout << m[1][n] << endl;
	return 0;
}