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

int main(){
	int n;
	cin >> n;
	int a[100][2];
	for ( int i = 0; i < n; i++ ) {
		cin >> a[i][0];
		cin >> a[i][1];
	}
	int c[100][100] = {0};
	for ( int i = 2; i <= n; i++ ) {
		for ( int j = 0; j <= n - i; j++ ) {
			int x = 0;
			for ( int k = 1; k < i; k++ ) {
				int y = 0;
				y = c[j][k] + c[j+k][i-k] + a[j][0] * a[j+k][0] * a[j+i-1][1];
				if ( x == 0 || x > y ) x = y;
			}
			c[j][i] = x;
		}
	}
	cout << c[0][n] << endl;
	return 0;
}

C++: /*
 * ALDS1_10_B.cpp
 *
 *  Created on: May 5, 2018
 *      Author: 13743
 */

#include<iostream>
#include<algorithm>

using namespace std;

struct Mat {
	int row;
	int col;
};

long mcm(Mat* M, int n) {
	long dp[101][101];
	for(int i=2; i<=n; i++) {
		for(int j=0; j<=n-i; j++) {
			dp[i][j] = 99999999999L;
			for(int k=1; k<i; k++) {
				dp[i][j] = min(dp[k][j]+dp[i-k][j+k]+M[j].row*M[j+k].row*M[j+i-1].col, dp[i][j]);
			}
		}
	}
	return dp[n][0];
}

long dpR[101][101];

long mcmRec(Mat* M, int l, int r) {
	if(r - l < 2) return 0;
	if(dpR[l][r] == 0) {
		dpR[l][r] = 9999999999L;
		for(int i=1; i<r-l; i++) {
			dpR[l][r] = min(mcmRec(M,l,l+i)+mcmRec(M,l+i,r)+M[l].row*M[l+i].row*M[r-1].col, dpR[l][r]);
		}
	}
	return dpR[l][r];
}

int main() {
	int n;
	Mat M[100];

	cin >> n;
	for(int i=0; i<n; i++) {
		cin >> M[i].row >> M[i].col;
	}

//	long ans = mcm(M, n);
	long ans = mcmRec(M, 0, n);
	cout << ans << endl;

}

C++: #include <stdio.h>
#include <limits.h>

#define min(a,b) ((a)<(b)?(a):(b))
#define N 100

int main(){
  int n,p[N+1],m[N+1][N+1];
  int j,i,l,k;
  scanf("%d",&n);

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

  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]=INT_MAX;
      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]);
      }
    }
  }
  printf("%d\n",m[1][n]);

  return 0;
}

C++: #include <bits/stdc++.h>
#define N 101
using namespace std;
int A[100];

int dp[N][N];

int Min(int &a,int b){return a = min(a,b);}

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

  for(int i=0,cnt=0;i<n;i++){
    int a,b;
    cin>>a>>b;
    if(i == 0) A[cnt++] = a;
    A[cnt++] = b;
  }

  for(int i=0;i<n+1;i++){
    for(int j=0;j<n+1;j++)dp[i][j] = 1e9;
    dp[i][i] = 0;
  }
  
  for(int len=0;len<n;len++)
    for(int l=1;l<n;l++){
      int r = l+len;
      for(int m = l;m<r;m++){
        Min(dp[l][r],dp[l][m] + dp[m+1][r] + A[l-1]*A[m]*A[r]);
      }
}
  
  cout<<dp[1][n]<<endl; 
  return 0;
}

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

int main(void){
	int i,j,k,n,p[101], m[101][101];
	scanf("%d", &n);
	for(i=0;i<n;i++){
		scanf("%d %d", &p[i], &p[i+1]);
	}
	
	for(i=n-2;i>=0;i--){
		m[i+1][i+1] = 0;
		for(j=i+1;j<n;j++){
			m[i][j] = p[i]*p[i+1]*p[j+1] + m[i+1][j];
			for(k=i+1;k<j;k++){
				m[i][j] = std::min(m[i][j], m[i][k] + m[k+1][j] + p[i]*p[k+1]*p[j+1]);
			}
		}
	}

	printf("%d\n", m[0][n-1]);

	return 0;
}

C++: #include <cassert>// c
#include <iostream>// io
#include <iomanip>
#include <fstream>
#include <sstream>
#include <vector>// container
#include <map>
#include <set>
#include <queue>
#include <bitset>
#include <stack>
#include <algorithm>// other
#include <complex>
#include <numeric>
#include <functional>
#include <random>
#include <regex>
using namespace std;

typedef long long ll;typedef unsigned long long ull;typedef long double ld;

#define ALL(c) c.begin(),c.end()
template<class T> bool IN(T l,T v,T r){return l<=v && v <r;}
template<class T> void UNIQUE(T v){v.erase(unique(ALL(v)),v.end());}
//debug
#define DUMP(x) cerr << #x <<" = " << (x)
#define LINE() cerr<< " (L" << __LINE__ << ")"

// values
template<typename T> inline T INF(){assert(false);};
template<> inline int INF<int>(){return 1<<28;};
template<> inline ll INF<ll>(){return 1LL<<58;};
template<> inline double INF<double>(){return 1e16;};
template<> inline long double INF<long double>(){return 1e16;};

template<class T> inline T EPS(){assert(false);};
template<> inline int EPS<int>(){return 1;};
template<> inline ll EPS<ll>(){return 1LL;};
template<> inline double EPS<double>(){return 1e-8;};
template<> inline long double EPS<long double>(){return 1e-8;};

// min{2^r | n < 2^r}
template<typename T> T upper_pow2(T n){ T res=1;while(res<n)res<<=1;return res;}
// max{d | 2^d  <= n}
template<typename T> T msb(T n){ int d=63;while((1LL<<d)>n)d--;return d;}

template<typename T,typename U> T pmod(T v,U M){return (v%M+M)%M;}

class Main{
	public:
	void run(){
		int N;cin >> N;
		vector<int> rs(N),cs(N);
		
		for(int i=0;i<N;i++)cin >> rs[i] >> cs[i];

		vector<vector<ll>> dp(N,vector<ll>(N+1,INF<ll>()));
		for(int l=0;l<N;l++) dp[l][l+1] = 0;

		for(int d=2;d<=N;d++)for(int l=0;l+d<=N;l++){
			int r = l+d;
			for(int m=l+1;m<r;m++){
				dp[l][r] = min(dp[l][r],dp[l][m] + rs[l] * rs[m] * cs[r-1] + dp[m][r]);
			}
		}
		cout << dp[0][N] <<endl;
	}
};

int main(){
	cout <<fixed<<setprecision(20);
	cin.tie(0);
	ios::sync_with_stdio(false);
	Main().run();
	return 0;
}

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

static const int N = 200;

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;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;
}