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>
#define N 110
using namespace std;
int A[N];
int dp[N][N];

int Min(int &a,int b){return a = min(a,b);}
int main(){
  int n;
  cin>>n;

  for(int i=0,cnt=0;i<n;i++){
    int a,b;
    cin>>a>>b;
    if(i == 0) A[cnt++] = a;
    A[cnt++] = b;
  }

  for(int i=0;i<N;i++){
    for(int j=0;j<N;j++)dp[i][j] = 1e9;
    dp[i][i] = 0;
  }
  
  for(int len=0;len<n;len++)
    for(int l=1;l<n;l++){
      int r = l+len;
      for(int m = l;m<r;m++){
        Min(dp[l][r],dp[l][m] + dp[m+1][r] + A[l-1]*A[m]*A[r]);
      }
}
  
  cout<<dp[1][n]<<endl; 
  return 0;
}

C++: #include <iostream>
#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 - 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]);
				}
			}
		}

		printf("%d\n", m[1][n]);

		return 0;
	}

C++: #include<iostream>
#include<algorithm>
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 <bits/stdc++.h>

using namespace std;

int main() {
    int n; 
    cin >> n; 
    int r, c;
    vector<pair<int, int>> v; 
    vector<int> dims; 
    for (int i = 0; i < n; ++i) { 
            cin >> r >> c; 
            if (i == 0) { 
                dims.push_back(r);
            } 
        dims.push_back(c);
    }
    // for (int i = 0; i < dims.size(); ++i)
    //     cout << dims[i] << " ";
    int dp[n][n];
    for (int i = 0; i < n; ++i)
        for (int j = 0; j < n; ++j)
            dp[i][j] = 0;
    
    for (int len = 2; len <= n; ++len) { 
        for (int i = 0; i <= n - len; ++i) { 
            int j = i + len-1;
            // cout << i << " " << j <<" -> ";
            dp[i][j] = INT_MAX;
            for (int k = i; k < j; ++k) { 
                // cout << dp[i][k] << " " << dims[i] << " " << dims[k+1] << " " << dims[j+1] << endl;
               int q = dp[i][k] + dp[k+1][j] + dims[i]*dims[k+1]*dims[j+1]; 
               dp[i][j] = min(q, dp[i][j]);
            }
        }
    }
    // for (int i = 0; i < n; ++i) {
    //     for (int j = 0;j < n; ++j)
    //         cout << dp[i][j] << " ";
    //     cout << endl;
    // }
    cout << dp[0][n-1] << endl;
   
}

C++: #include<bits/stdc++.h>

using namespace std;
#define rep(i,n) for(int i=0;i<(n);i++)

#define MAX 100005
#define INF INT_MAX

typedef long long ll;
typedef pair<int, int> P;

P a[MAX];
map<P, int> memo;

int minMultTime(int s, int e)
{
    if (s >= e) return 0;
    if (memo[P(s,e)]) return memo[P(s,e)];

    int ans = INF;
    rep(i,e-s) {
        int m1 = minMultTime(s,s+i);
        int m2 = minMultTime(s+i+1,e);
        int m3 = a[s].first * a[s+i].second * a[e].second;
        ans = min(ans, m1+m2+m3);
    }
    memo[P(s,e)] = ans;

    return ans;
}

int main(int, char**)
{
    int n;
    cin >> n;

    rep(i,n) {
        cin >> a[i].first;
        cin >> a[i].second;
    }

    cout << minMultTime(0, n-1) << endl;

    return 0;
}

C++: #include <bits/stdc++.h>
#define INF 1000000000
typedef long long ll;
using namespace std;

int main()
{
	ll n;
	cin >> n;
	vector<ll> M(n + 1);
	cin >> M[0];
	for (int i = 1; i < n; i++) {
		cin >> M[i] >> M[i];
	}
	cin >> M[n];
	vector<vector<ll>> dp(n, vector<ll>(n, INF));
	for (int i = 0; i < n; i++) {
		dp[i][i] = 0;
	}
	for (ll k = 1; k < n; k++) {
		for (ll i = 0; i + k < n; i++) {
			for (ll j = 0; j <= i + k - 1; j++) {
				ll cost = dp[i][j] + dp[j + 1][i + k] + M[i] * M[j + 1] * M[i + k + 1];
				if (cost < dp[i][i + k]) {
					dp[i][i + k] = cost;
				}
			}
		}
	}
	cout << dp[0][n - 1] << endl;
	return 0;
}