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;

using ll = long long;

template<typename T> using V = std::vector<T>;
using Vi = V<int>;
using VVi = V<V<int>>;
using Vl = V<ll>;
using VVl = V<V<ll>>;
using Vs = V<string>;

template<typename T1, typename T2> using P = std::pair<T1, T2>;
using Pii = P<int, int>;
using Pll = P<ll, ll>;
using Pdd = P<double, double>;

template<typename T1, typename T2> using M = std::map<T1, T2>;
using Mii = M<int, int>;
using Msi = M<string, int>;

#define REP(i,n) for(int i=0;i<(int)(n);++i)
#define REP2(i,s,e) for(int i=(int)(s);i<(int)(e);++i)
#define RREP(i,s,e) for(int i=(int)(s);i>=(int)(e);--i)
#define FOR(i,c) for(__typeof((c).begin())i=(c).begin(),ie=(c).end();i!=ie;++i)
#define ALL(c) (c).begin(), (c).end()

const double PI = acos(-1);
const ll MOD = 1e9+7;

int n;
string s;

struct X {
    int r, c;
    ll cost;
};

int main() {
    cin >> n;
    V<Pii> v(n);
    REP(i, n) {
        int r, c;
        cin >> r >> c;
        v[i] = {r, c};
    }

    V<V<X>> dp(n, V<X>(n));
    REP(i, n) {
        X x = {v[i].first, v[i].second, 0LL};
        dp[i][i] = x;
    }
    REP2(k, 1, n) {
        REP(i, n-k) {
            int R = dp[i][i].r, C = dp[i+k][i+k].c;
            X x = {R, C, (ll)1e18};
            REP2(j, i, i+k) {
                ll cost = dp[i][j].cost + dp[j+1][i+k].cost + R*C*dp[i][j].c;
                if (x.cost > cost) {
                    x.cost = cost;
                }
            }
            dp[i][i+k] = x;
        }
    }
    std::cout << dp[0][n-1].cost << '\n';

    return 0;
}

C++: #include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <cmath>
#include <cassert>
#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,n) FOR(i,0,n)
#define rep(i,n) FOR(i,0,n)
#define DEBUG(x) cout<<#x<<": "<<x<<endl
#define vint vector<int>
#define vdouble vector<double>
#define vstring vector<string>
using namespace std;

#include<map>
#include<set>
#include<queue>

typedef long long ll;
typedef unsigned long long ull;

const int MAX_N = 1000000;
const int MAX_L = 10000;
int N;

struct Matrix{ int R, W; };
Matrix M[MAX_N];

int mem[MAX_L][MAX_L];
Matrix memM[MAX_L][MAX_L];


void eval(Matrix M[], int s, int e){

	if (s == e){
		mem[s][e] = 0;
		memM[s][e] = M[s];
		return;
	}

	int minval = 1000000000;
	for (int mid = s; mid < e; mid++){
		Matrix m1 = memM[s][mid];
		Matrix m2 = memM[mid+1][e];
		int val = mem[s][mid] + mem[mid+1][e] + (m1.W * m1.R * m2.W);
		
		if (val < minval){
			minval = val;
			mem[s][e] = val;
			Matrix m; m.R = m1.R; m.W = m2.W;
			memM[s][e] = m;
		}
	}

}

int solve(Matrix M[], int N){

	for (int d = 0; d <= N; d++)
		for (int s = 0; s + d <= N; s++)
		{
			eval(M, s, s + d);
		}

	return mem[0][N];
}

int main() {

	cin >> N;
	rep(i, N){
		Matrix m;
		cin >> m.R;
		cin >> m.W;
		M[i] = m;
	}

	cout << solve(M, N) << endl;

#ifdef DEBUGRUN
	rep (i, N){
		rep(j, N){
			cerr << mem[i][j] << ' ';
		}
		cerr << endl;
	}
#endif

}

C++: #include <bits/stdc++.h>
typedef long long ll;
using namespace std;
 
 
int main()
{
    int n;
    cin >> n;
    vector<int> p(n + 1);
    for(int i = 0; i <= n; i++){
        int a,b;
        cin >> a >> b;
        if(!i) {
         p[i] = a;
         i++;
        }
        p[i] = b;
    }
    
    vector<vector<int>> m(n + 1, vector<int>(n + 1, 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;
#define MOD 1000000007

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

 vector<long long> p(n+1);
 for(int i = 1;i <= n;i++) {
   cin >> p.at(i-1) >> p.at(i);
 }

 vector<vector<long long> > dp(n+1,vector<long long>(n+1,0));

 for(int l = 2;l <= n;l++) {
   for(int i = 1;i <= n-l+1;i++) {
     int j = i + l - 1;
     dp[i][j] = (1<<21);
     for(int k = i;k <= j-1;k++) {
       dp[i][j] = min(dp[i][j],dp[i][k]+dp[k+1][j]+p[i-1] * p[k] * p[j]);
     }
   }
 }

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