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;
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 -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 range(i,a,b) for(int i = (a); i < (b); i++)
#define rep(i,b) for(int i = 0; i < (b); i++)
#define all(a) (a).begin(), (a).end()
#define show(x)  cerr << #x << " = " << (x) << endl;
//const int INF = 1e8;
using namespace std;

// O(n^3)
// dp[i][j] := [i,j]????????????????????????????°?????????????????????°
// i??????????????????(?????°????????°)??????(p[i - 1], p[i])
int matrixChainMultiplication(int n, int p[105]){
    int dp[105][105] = {{0}};
    range(seg, 2, n + 1){ //?¨????????????????????????°
        range(i, 1, n - seg + 2){
            int j = i + seg - 1;
            dp[i][j] = INT_MAX;
            range(k,i,j){
                int cost = dp[i][k] + dp[k + 1][j] + p[i - 1] * p[k] * p[j];
                dp[i][j] = min(dp[i][j], cost);
            }
        }
    }
    return dp[1][n];
}

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

    int p[105];
    rep(i,n){
        cin >> p[i] >> p[i + 1];
    }
    cout << matrixChainMultiplication(n, p) << endl;
}

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<iostream>
#include<algorithm>
using namespace std;

int nlist[110];
int dp[110][110];

int main(){
  int n;
  cin>>n;
  for(int i=0;i<n;i++){
    cin>>nlist[i]>>nlist[i+1];
  }
  for(int i=1;i<n;i++){
    for(int j=0;j<n-i;j++){
      dp[j][j+i]=1<<30;
      for(int k=0;k<i;k++){
	dp[j][j+i]=min(dp[j][j+i],dp[j][j+k]+dp[j+k+1][j+i]+nlist[j]*nlist[j+k+1]*nlist[j+i+1]);
      }
    }
  }
  cout<<dp[0][n-1]<<endl;
  return 0;
}

C++: #include <iostream>

using namespace std;

int m[124][124] = {{}};
int p[124] = {};
int n;

void chain(){
  for(int i = 0 ;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;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;

}


int main(){

  cin >> n;

  for(int i = 1;i <= n;i++){
    cin >> p[i - 1] >> p[i];
  }

  chain();

}

C++: #include<iostream>
#include<algorithm>
using namespace std;

static const int N=100;

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 <stdio.h>
#include <algorithm>

const int N = 100;
int n, p[N + 1], dp[N + 1][N + 1];

int main()
{
	scanf("%d", &n);
	for (int i = 1; i <= n; i++)
		scanf("%d%d", &p[i - 1], &p[i]);

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

	for (int k = 2; k <= n; k++)
	{
		for (int i = 1; i <= n - k + 1; i++)
		{
			int j = i + k - 1;
			dp[i][j] = 1 << 20;
			for (int s = i; s <= j - 1; s++)
				dp[i][j] = std::min(dp[i][j], dp[i][s] + dp[s + 1][j] + p[i - 1] * p[s] * p[j]);
		}
	}
	printf("%d\n", dp[1][n]);

	return 0;
}

C++: #include <iostream>
using namespace std;
#define INF 10000000

int M[101][101],p[101];

int main() {
  int n; 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] = INF;
      for ( int k = i; k <= j-1; k++ ) {
	int q = M[i][k] + M[k+1][j] + p[i-1]*p[k]*p[j];
	M[i][j] = min(M[i][j],q);
      }
    }
  }
  cout << M[1][n] << endl;
  return 0;
}

C++: #include<iostream>
#include<algorithm>
using namespace std;

#define INF (100 * 100 * 100 * 100)

int n, m[110][110];

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

int main(){
  
  int p[110];
  
  cin >> n;
  
  for(int i = 0;i < n;i++){
    int r, c;
    
    cin >> r >> c;
    if(i) p[i + 1] = c;
    else{
      p[0] = r;
      p[1] = c;
    }
  }
  
  matrixChainOrder(p);
  
  cout << m[1][n] << endl;
  
  return 0;
}

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

using namespace std;

static const int N = 100;
static int m[N + 1][N + 1] = {}, p[N + 1] = {};

static inline void matrixChainMultiplication(int n) {
  for (int l = 2; l <= n; l++) {
    for (int i = 1; i <= n - l + 1; i++) {
      int j = i + l - 1;
      m[i][j] = INT_MAX;
      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]); 
      }
    }
  }
}

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

  matrixChainMultiplication(n);
  
  cout << m[1][n] << endl;

  return 0;
}