Go: package main

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

const (
	initialBufSize = 100000
	maxBufSize     = 1000000
)

var sc *bufio.Scanner

func initScanner(r io.Reader) *bufio.Scanner {
	buf := make([]byte, initialBufSize)

	sc := bufio.NewScanner(r)
	sc.Buffer(buf, maxBufSize)
	sc.Split(bufio.ScanWords) // bufio.ScanLines
	return sc
}

func main() {
	sc = initScanner(os.Stdin)
	fmt.Println(resolve(parseProblem()))
}

type matrixSize struct{ row, col int }

func calcNum(i, j matrixSize) int {
	return i.row * j.col * i.col
}

func parseProblem() (int, []matrixSize) {
	n := scanInt(sc)
	sizes := make([]matrixSize, n)
	for i := 0; i < n; i++ {
		sizes[i] = matrixSize{row: scanInt(sc), col: scanInt(sc)}
	}
	return n, sizes
}

var dp [][]int

func initDP(n int) {
	dp = make([][]int, n+1)
	for i := 0; i < len(dp); i++ {
		dp[i] = make([]int, n+1)
		for j := 0; j < len(dp[i]); j++ {
			dp[i][j] = math.MaxInt64
		}
	}
}

func resolve(n int, sizes []matrixSize) int {
	// TODO 復習
	initDP(n)
	_rec(sizes, 0, n)
	return dp[0][n]
}

func _rec(sizes []matrixSize, l, r int) int {
	if dp[l][r] != math.MaxInt64 {
		return dp[l][r]
	}
	if r-l <= 1 {
		dp[l][r] = 0
		return 0
	}
	num := math.MaxInt64
	for i := l + 1; i < r; i++ {
		v := _rec(sizes, l, i) + _rec(sizes, i, r) + calcNum(matrixSize{sizes[l].row, sizes[i].row}, matrixSize{sizes[i].row, sizes[r-1].col})
		if v < num {
			num = v
		}
	}
	dp[l][r] = num
	return dp[l][r]
}

// snip-scan-funcs
func scanInt(sc *bufio.Scanner) int {
	sc.Scan()
	i, _ := strconv.Atoi(sc.Text())
	return int(i)
}
func scanString(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

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 ( 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 <iostream>
#include <cstdlib>
#include <vector>
using namespace std;

struct matrix_size{
	int row;
	int col;
};

int matrixchaincost(vector <matrix_size> &M){
	int n=M.size();
	vector < vector <int> > cost(n, vector <int> (n));
	vector < vector <matrix_size> > X(n, vector <matrix_size> (n));
	for (int i=0; i<n; i++){
		cost[i][i] = 0;
		X[i][i] = M[i];
	}

	for (int length=2; length<=n; length++){
		for (int i=0; i+length<=n; i++){
			int j = i+length-1;
			X[i][j].row = X[i][i].row;
			X[i][j].col = X[j][j].col;
			if (X[i][j-1].col != X[j][j].row){
				cout<<"error"<<endl;
				return NULL;
			}
			int k = i+1;
			int mincost = X[i][k-1].row * X[i][k-1].col * X[k][j].col + cost[i][k-1] + cost[k][j];
			k++;
			while (k<=j){
				int tmp = X[i][k-1].row * X[i][k-1].col * X[k][j].col + cost[i][k-1] + cost[k][j];
				if (tmp<mincost)
					mincost = tmp;
				k++;
			};
			cost[i][j] = mincost;
		}
	}
	return cost[0][n-1];
}

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

	vector <matrix_size> M(n);

	for (int i=0; i<n; i++){
		cin>>M[i].row;
		cin>>M[i].col;
	}
	cout<<matrixchaincost(M);
	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++: #define _USE_MATH_DEFINES
#include <iostream>
#include <string>
#include <utility>
#include <stack>
#include <vector>
#include <queue>
#include <algorithm>
#include <map>
#include <climits>
#include <set>
#include <cmath>
#include <numeric>
#include <iomanip>

using namespace std;
int r[100];
int c[100];
int dp[100][100];
int main(void){
  int n;
  cin >> n;
  for(int i = 0; i < n; i++){
    cin >> r[i] >> c[i];
  }

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

  for(int i = 1; i < n; i++){
    for(int j = 0; j <= n - i - 1; j++){
      for(int k = j; k < j + i; k++){
        dp[j][j + i] = min(dp[j][j + i], dp[j][k] + dp[k + 1][j + i] + r[j] * c[k] * c[j + i]);
      }
    }
  }
  cout << dp[0][n - 1] << endl;
  return 0;
}

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

static const int N = 1000;
#define INF (1 << 20)

int p[N];
int m[N][N];

int main() {
    int n; std::cin >> n;
    for(int i = 1; i <= n; i++) {
        std::cin >> p[i-1] >> p[i];
    }
    for(int i = 0; i < N; i++) {
        for(int j = 0; j < N; j++) {
            m[i][j] = 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] = INF;
            for(int k = i; k <= j - 1; k++) {
                m[i][j] = std::min(m[i][j], m[i][k] + m[k+1][j] + p[i-1] * p[k] * p[j]);
            }
        }
    }
    std::cout << m[1][n] << std::endl;
    return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
int main(){
    int n;scanf("%d",&n);
    vector<pair<int,int>> m(n);
    for(int i=0;i<n;i++)scanf("%d%d",&m[i].first,&m[i].second);
    int dp[n][n];
    fill(dp[0],dp[0]+n*n,1e9);
    for(int i=0;i<n;i++)dp[i][i]=0;
    for(int k=1;k<n;k++){
        for(int i=0;i<n-k;i++){
            int j=i+k;
            for(int l=i;l<j;l++){
                dp[i][j]=min(dp[i][j],dp[i][l]+dp[l+1][j]+m[i].first*m[l].second*m[j].second);
            }
        }
    }
    printf("%d\n",dp[0][n-1]);
    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>
#define INF 1e9
using namespace std;


int main(){
  int n;
  cin>>n;
  int a[105];
  for(int i=1;i<=n;i++)cin>>a[i-1]>>a[i];

  int dp[105][105]={};
  for(int i=0;i<105;i++)
    for(int j=0;j<105;j++)dp[i][j]=INF*(i!=j);

  for(int l=0;l<n;l++){
    for(int i=0;i<n-l;i++){
      int j=i+l;
      for(int k=i;k<j;k++){
	dp[i][j]=min(dp[i][j],dp[i][k]+dp[k+1][j]+a[i]*a[k+1]*a[j+1]);
      }
    }
  }

  cout << dp[0][n-1]<<endl;
  return 0;
}