Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

//util
var sc = bufio.NewScanner(os.Stdin)

func nextStr() string {
	sc.Scan()
	return sc.Text()
}

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func printList(list []int) {
	buf := bufio.NewWriter(os.Stdout)
	for _, v := range list {
		buf.Write([]byte(fmt.Sprintf(" %d", v)))
	}
	buf.Write([]byte("\n"))
	buf.Flush()
}

//solve
//単純な場合
func matrixChainMultiplication() {
	//行列が1つだけのとき
	for i := 1; i <= n; i++ {
		m[i][i] = 0
	}
	for l := 2; l <= n; l++ {
		for i := 1; i <= n-l+1; i++ {
			j := i + l - 1
			m[i][j] = 1 << 21
			//kまでで区切る
			for 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])
			}
		}
	}
}

func max(a, b int) int {
	if a > b {
		return a
	} else {
		return b
	}
}

func min(a, b int) int {
	if a > b {
		return b
	} else {
		return a
	}
}

const MAX = 100

var n int
var p [MAX + 1]int

//m[i][j]: Mi * Mi+1 * ... * Mjを計算するときに必要なスカラー乗算の最小回数
var m [MAX + 1][MAX + 1]int

func main() {
	sc.Split(bufio.ScanWords)
	n = nextInt()
	for i := 1; i <= n; i++ {

		p[i-1] = nextInt() //行数
		p[i] = nextInt()   //列数
	}

	matrixChainMultiplication()
	fmt.Println(m[1][n])
}

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

#define rep(i,n) for(int i=0;i<(n);i++)
using namespace std;
const int INF=1e9;
int n;
int r[102],c[102];
int p[102];

int dp[102][102];
// [i,j)
int dfs(int i,int j) {
    //cout<<i<<", "<<j<<endl;
    if(dp[i][j]!=-1) return dp[i][j];
    if(j-i==1) return r[i]*c[i]*c[j-1];
    if(i==j) return 0;
    int ret=INF;
    for(int k=i+1;k<j;k++) {
        //ret=min(ret,dfs(i,k)+dfs(k,j)+r[i]*c[k]*c[j-1]);
        ret=min(ret,dfs(i,k)+dfs(k,j)+p[i]*p[k]*p[j]);
    }

    return dp[i][j]=ret;
}

int main() {
    memset(dp,-1,sizeof(dp));
    cin>>n;
    //rep(i,n) cin>>r[i]>>c[i];
    rep(i,n+1) if(i) cin>>p[i-1]>>p[i];
    cout<<dfs(0,n)<<endl;
    return 0;
}

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

using Lint=long long;
const int INF=1e9;

int main()
{
   int N; cin>>N;
   vector<int> row(N),col(N);
   for(int i=0;i<N;i++) cin>>row[i]>>col[i];

   vector<vector<int>> dp(N+1,vector<int>(N+1,INF));
   for(int i=0;i<N;i++) dp[i][i+1]=0;
   for(int len=2;len<=N;len++){
      for(int l=0;l+len<=N;l++){
         int r=l+len;
         for(int m=l+1;m<r;m++) dp[l][r]=min(dp[l][r],dp[l][m]+dp[m][r]+row[l]*row[m]*col[r-1]);
      }
   }
   cout<<dp[0][N]<<endl;
   return 0;
}

C++: #include <stdio.h>

#define MAX 101
#define INF 10000000;


void MatrixChainOrder();
int min(int,int);

int m[MAX][MAX];
int p[MAX];

int n;

int main(){

  int i,j,r,c;

  scanf("%d",&n);

  for(i=0;i<n;i++){
    scanf("%d%d",&r,&c);
    p[i]=r;
    p[i+1]=c;
  }

  MatrixChainOrder();

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

  return 0;
}


void MatrixChainOrder(){

  int i,j,k,l,q;

  for(i=1;i<=n;i++) m[i][i]=0;

  for(l=2;l<=n;l++){

    for(i=1;n-l+1;i++){
      j=i+l-1;
      m[i][j]=INF;

      for(k=i;k<=j-1;k++){
	q=m[i][k]+m[k+1][j]+p[i-1]*p[k]*p[j];
	m[i][j]=min(m[i][j],q);
}
}
}

}

int min(int x,int y){

  if(x<=y) return x;
  else return y;

}

C++: #include <cstdio>
#include <iostream>
#include <algorithm>
#include <cstring>
using namespace std;
const int maxx=2000000000;

int n;
int p[110],dp[110][110];

int main (){
	cin>>n;
	for(int i=1;i<=n;i++){
		dp[i][i]=0;
		cin>>p[i-1]>>p[i];
	}
	for(int len=2;len<=n;len++){
		for(int i=1;i<=n-len+1;i++){
			int j=i+len-1;
			dp[i][j]=maxx;
			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]);
		}
	}
	cout<<dp[1][n]<<endl;
	return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
#define INFTY 200000000000
long long dp[110][110];
int seen[110][110];
vector<int>ro(110),co(110);
long long ch(int l,int r){
    long long mn = dp[l][r];
    if(r==l) return dp[l][r] = 0;
    if(dp[l][r]!=INFTY) return dp[l][r];
    for (int k = l; k < r; k++)
    {
        long long sum = ch(l,k)+ch(k+1,r)+ro[l]*co[r]*ro[k+1];
        mn = min(mn,sum);
    }  
    return dp[l][r] = mn;
}
int main(){
    int n;cin >> n;
    for (int i = 0; i < n; i++)
    {
        cin >> ro[i]>>co[i];
    }
    
    for (int i = 0; i < n;i++)
    {
        for(int j=0;j<n;j++){
            dp[i][j] = INFTY;
        }
        }
    long long ans = ch(0,n-1);
    cout << ans << endl;

    return 0;
}

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;







}