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<bits/stdc++.h>
using namespace std;
#define INF 1000000000
#define mp make_pair
#define fi first
#define se second

int main()
{
    int n;cin >> n;
    vector<pair<int,int>> matrix(n);
    int a,b;
    for (int i=0;i<n;i++)
    {
        cin >> a >> b;
        matrix[i]=mp(a,b);
    }
    vector<vector<pair<int,pair<int,int>>>> dp(n,vector<pair<int,pair<int,int>>> (n,mp(INF,mp(-1,-1))));
    for (int i=0;i<n;i++)
    {
        dp[i][i].fi=0;
        dp[i][i].se.fi=matrix[i].fi;
        dp[i][i].se.se=matrix[i].se;
    }
    for (int len=1;len<n;len++)
    {
        for (int l=0;l<n-len;l++)
        {
            int r=l+len;
            //cout << l << r << endl;
            for (int m=l;m<r;m++)
            {
                if (dp[l][r].fi>dp[l][m].fi+dp[m+1][r].fi+dp[l][m].se.fi*dp[l][m].se.se*dp[m+1][r].se.se)
                {
                    //cout << l <<" " << r << ":" ;
                    dp[l][r].fi=dp[l][m].fi+dp[m+1][r].fi+dp[l][m].se.fi*dp[l][m].se.se*dp[m+1][r].se.se;
                    dp[l][r].se.fi=dp[l][m].se.fi;
                    dp[l][r].se.se=dp[m+1][r].se.se;
                    //cout << dp[l][r].fi<< endl;
                }
            }
        }
    }
    cout << dp[0][n-1].fi << endl;
    return 0;
}

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

constexpr int INF = 1e9;

int dp[110][110];

int main(){
  int n; cin >> n;
  int p[110];
  for( int i = 0; i < n; i++ ) cin >> p[i] >> p[i + 1];
  for( int i = 0; i < 110; i++ ){
    for( int j = 0; j < 110; j++ ){
      if( i != j ) dp[i][j] = INF;
    }
  }
  
  for( int l = 2; l <= n; l++ ){
    for( int i = 0; i < n - l + 1; i++ ){
      int j = l + i - 1;
      for( int k = i; k < j; k++ ){
	dp[i][j] = min( dp[i][j], dp[i][k] + dp[k + 1][j] + p[i] * p[k + 1] * p[j + 1] );
      }
    }
  }

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

C++: #include<iostream>
#include<algorithm>
using namespace std;
#define INF 1<<30

static const int N = 100;

int main() {
    int n;
    int 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] = INF;
            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;

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;
#define 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[i][k] + m[k + 1][j] + p[i - 1] * p[k] * p[j]);
			}
		}
	}
	cout << m[1][n] << endl;
	return 0;
}