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++: /*
　　　∫ ∫ ∫
　　　ノヽ
　　（＿　 ）
　（＿　　　 ）
（＿＿＿＿＿＿ ）
　ヽ(´･ω･)ﾉ　
　　 |　 /
　　 UU
*/
#include <bits/stdc++.h>
typedef long long ll;
using namespace std;
using P = pair<ll, ll>;
const int MOD = (int)1e9 + 7;
const ll INF = 1LL << 60;
const int inf = 1<<30;
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
#define REP(i, n) for (int i = 0; i < (n); i++)
#define FOR(i,s,n) for (int i = s; i < (n); i++)
#define ALL(obj) (obj).begin(), (obj).end() //コンテナじゃないと使えない!!
#define debug(x) cerr << #x << ": " << x << "\n";
#define mp make_pair
template <typename T>
ostream& operator<<(ostream& os, vector<T> &V){
    int N = V.size();
    REP(i,N){
        os << V[i];
        if (i!=N-1) os << " ";
    }
    os << "\n";
    return os;
}
template <typename T>
ostream& operator<<(ostream& os, pair<T,T> const&P){
    os << P.first;
    os << " ";
    os << P.second;
    return os;
}
template <typename T>
ostream& operator<<(ostream& os, set<T> &S){
    auto it=S.begin();
    while(it!=S.end()){
        os << *it;
        os << " ";
        it++;
    }
    os << "\n";
    return os;
}
template <typename T>
ostream& operator<<(ostream& os, deque<T> &q){
    for(auto it=q.begin();it<q.end();it++){
        os<<*it;
        os<<" ";
    }
     os<<endl;
    return os;
}
//fixed<<setprecision(10)<<ans<<endl;
int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    int N;
    cin >> N;
    vector<int> A(N+1);
    REP(i,N){
        int a,b;
        cin >> a >> b;
        A[i]=a;
        A[i+1]=b;
    }

    int ans=0;
    vector<vector<int>> dp(N,vector<int>(N,inf));
    REP(i,N) dp[i][i]=0;

    for(int i=1;i<N;i++){
        for(int left=0;left<N-i;left++){
            int right = left+i;
            for(int k=0;k<i;k++){
                int mid = left+k;
                chmin(dp[left][right], dp[left][mid] + A[left]*A[mid+1]*A[right+1] + dp[mid+1][right] );
            }
        }
    }
    ans = dp[0][N-1];
    cout << ans << endl;
}

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

template<class T> inline void chmin(T &a, const T &b) { if(a > b) a = b; }

int mul(const int r1, const int c1, const int r2, const int c2) {
	assert(c1 == r2);
	return r1 * c2 * r2;
}

int main() {
	int n;
	cin >> n;

	vector<int> R(n), C(n);
	for(int i = 0; i < n; ++i) {
		cin >> R[i] >> C[i];
	}

	constexpr int INF = (1 << 29);
	vector<vector<int>> dp(n, vector<int>(n + 1, INF));
	for(int i = 0; i < n; ++i) {
		dp[i][i + 1] = 0;
	}

	for(int len = 0; len <= n; ++len) {
		for(int l = 0; l + len <= n; ++l) {
			const int r = l + len;
			for(int i = l + 1; i < r; ++i) {
				chmin(dp[l][r], dp[l][i] + dp[i][r] + mul(R[l], C[i - 1], R[i], C[r - 1]));
			}
		}
	}

	cout << dp[0][n] << endl;

	return EXIT_SUCCESS;
}

C++: #include<bits/stdc++.h>
using namespace std;
#define MAXN 102
#define INF 10000000
int dp[MAXN][MAXN];
int p[MAXN];
int main(){
    int n;
    scanf("%d", &n);
    scanf("%d", p);
    int x;
    for(int i = 1; i < n; i++)
        scanf("%d%d", &x, p + i);
    scanf("%d", p + n);
    for(int i = 1; i <= n; i++)
        dp[i][i] = 0;
    for(int l = 1; l < n; l++){
        for(int i = 1; i + l <= n; i++){
            int j = i + l;
            dp[i][j] = INF;
            for(int k = i; k < j; k++){
                dp[i][j] = min(dp[i][j], dp[i][k] + dp[k + 1][j] + p[i - 1] * p[k] * p[j]);
            }
        }
    }
    printf("%d\n", dp[1][n]);
    return 0;
}

C++: #include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

#define INF 1e9

int main(){
  int n;

  cin >> n;
  vector<int> r(n),c(n),p;
  for(int i = 0 ; i < n ; i++){
    cin >> r[i] >> c[i];
  }

  p.push_back(r[0]);
  for(int i = 0 ; i < n ; i++){
    p.push_back(c[i]);
  }

  int dp[n+1][n+1];
  for(int i = 0 ; i <= n ; i++){
    dp[i][i] = 0;
  }

  for(int l = 2 ; l <= n ; l++){
    for(int i = 1 ; i <= n-l+1 ; i++){
      int j = i + l - 1;
      dp[i][j] = INF;
      for(int k = i ; k <= j-1 ; k++){
	int cost = dp[i][k] + dp[k+1][j] + p[i-1]*p[j]*p[k];
	dp[i][j] = min(dp[i][j],cost);
      }
    }
  }

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

  return 0;
}