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>
typedef long long ll;
typedef long double ld;
#define rep(i,n) for(ll i=0;i<(n);i++)
#define repr(i,n) for(ll i=(n-1);i>=0;i--)
#define all(x) x.begin(),x.end()
#define br cout << "\n";
using namespace std;
const int INF = 1e9;
const int MOD = 1e9+7;
using Graph = vector<vector<ll>>;
template<class T> inline bool chmin(T &a, T b) { if(a > b){ a = b; return true;} return false;}
template<class T> inline bool chmax(T &a, T b) { if(a < b){ a = b; return true;} return false;}

// 0 false, 1 true 
// string to int : -48
// ceil(a)  1.2->2.0
// c++17	g++ -std=c++17 a.cpp

ll n;
vector<vector<ll>> dp(n, vector<ll>(n, INF));  //dp[i][j] i to j min cost
vector<pair<ll,ll>> vec(n);

ll calc_mult(pair<ll,ll> a, pair<ll,ll> b){
    return a.first * a.second * b.second;
}

ll calc_sec(ll a, ll b){
    if(dp[a][b] != -1){
        return dp[a][b];
    }
    if(b == a){
        return 0;
    }
    if(b - a == 1){
        dp[a][b] = vec[a].first * vec[a].second * vec[b].second;
        return vec[a].first * vec[a].second * vec[b].second;
        //return 0;
    }


    ll res = INF;
    for(ll i = a; i < b; i++){
        res = min(res, calc_sec(a, i) + calc_sec(i+1, b) + vec[a].first * vec[i].second * vec[b].second);
    }

    dp[a][b] = res;
    return res;
}


int main() {
    std::cout << std::fixed << std::setprecision(15);
    cin >> n;

    vec.resize(n);
    rep(i, n) cin >> vec[i].first >> vec[i].second;

    if(n == 1){
        cout << 0 << endl;
        return 0;
    }

    
    dp.resize(n, vector<ll>(n));
    dp.assign(n, vector<ll>(n, -1));
    rep(i,n){
        dp[i][i] = 0;
    }

    /*
    cout << calc_sec(0, 1) << endl;
    cout << calc_sec(0, 2) << endl;
    cout << calc_sec(0, 5) << endl;
    */
    /*
    rep(i,n){
        rep(j,n){
            cout << dp[i][j] << " ";
        }
        br;
    }
    */

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







}

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

//using Graph = vector<vector<edge>>;
using dou =long double;
string yes="yes";
string Yes="Yes";
string YES="YES";
string no="no";
string No="No";
string NO="NO";

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }
#define rep(i, n)         for(int i = 0; i < (int)(n); i++)
#define brep(n)           for(int bit=0;bit<(1<<n);bit++)
#define erep(i,container) for (auto i : container)
#define irep(i, n)        for(int i = n-1; i >= (int)0; i--)
#define rrep(i,m,n) for(ll i = m; i < (ll)(n); i++)
#define reprep(i,j,h,w) rep(i,h)rep(j,w)
#define all(x) (x).begin(),(x).end()
#define VEC(type,name,n) std::vector<type> name(n);rep(i,n)std::cin >> name[i];
#define pb push_back
#define pf push_front
#define query int qq;std::cin >> qq;rep(qqq,qq)
#define lb lower_bound
#define ub upper_bound
#define fi first
#define se second
#define itn int
#define mp make_pair
#define sum(a) accumulate(all(a),0ll)
#define keta fixed<<setprecision
#define vvector(name,typ,m,n,a)vector<vector<typ> > name(m,vector<typ> (n,a))
#define vvvector(name,t,l,m,n,a) vector<vector<vector<t> > > name(l, vector<vector<t> >(m, vector<t>(n,a)));
#define vvvvector(name,t,k,l,m,n,a) vector<vector<vector<vector<t> > > > name(k,vector<vector<vector<t> > >(l, vector<vector<t> >(m, vector<t>(n,a)) ));
#define case std::cout <<"Case #" <<qqq+1<<": "
#define res resize
#define as assign
#define ffor for(;;)
#define ppri(a,b) std::cout << a<<" "<<b << std::endl
#define pppri(a,b,c) std::cout << a<<" "<<b <<" "<< c<<std::endl
#define aall(x,n) (x).begin(),(x).begin()+(n)
#define ssum(a) accumulate(a,0ll) 

typedef long long ll;
typedef pair<int,int> P;
typedef pair<ll,ll> PL;
//typedef long long T;
const int INF = 2000000000;
const ll INF64 = 922337203685477580ll;
const ll MOD = 1000000007ll;
const dou pi=3.141592653589793;
int main(){
    int n;
    std::cin >> n;
    std::vector<int> a(n),b(n);
    rep(i,n)std::cin >> a[i]>>b[i];
    vvector(dp,int,n+1,n+1,INF);
    rep(i,n+1)dp[i][i]=0;
    rep(i,n)dp[i][i+1]=0;
    rep(i,n-1){
        dp[i][i+2]=a[i]*b[i]*b[i+1];
     //   std::cout << dp[i][i+2] << std::endl;
    }
    
    rrep(i,3,n+1){
        rep(j,n-i+1){
            //dp[j][j+i]=min(dp[j][j+i-1]+a[j]*a[j+i-1]*b[j+i-1],dp[j+1][j+i]+b[j+i-1]*a[j]*b[j]);
            rrep(ii,j+1,i+j)chmin(dp[j][j+i],dp[j][ii]+dp[ii][j+i]+a[j]*b[j+i-1]*a[ii]);
        }
    }
    std::cout << dp[0][n] << std::endl;
    
}

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

using namespace std;

int main(){
  int N; cin >> N;
  int dp[101][101];
  fill((int*)dp, (int*)dp+101*101, 1234567890);

  vector<int> r(N), c(N);
  for(int i=0;i<N;++i){
	cin >> r[i] >> c[i];
	dp[i][i+1] = 0;
  }
  
  for(int l=2;l<=N;++l){
	for(int i=0;i+l<=N;++i){
	  for(int j=i+1;j<i+l;++j){
		dp[i][i+l] = min(dp[i][j] + dp[j][i+l] + r[i]*c[i+l-1]*r[j], dp[i][i+l]);
	  }
	}
  }
  cout << dp[0][N] << endl;
  
  return 0;
}