Go: package main

/*
連鎖行列積
*/

import (
	"bufio"
	"bytes"
	"fmt"
	"log"
	"math"
	"os"
	"strconv"
	"strings"
)

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

type mem *[][]int

func main() {
	scanner := makeScanner(1024)
	n := eGetInt(scanner)
	p := make([]int, n+1)
	for i := 0; i < n; i++ {
		rowcol := eGetInts(scanner)
		p[i] = rowcol[0]
		p[i+1] = rowcol[1]
	}
	m := make([][]int, n)
	for i := 0; i < n; i++ {
		m[i] = make([]int, n)
	}
	// 初期値の格納
	for i := 0; i < n; i++ {
		for j := i; j < n; j++ {
			if i == j {
				m[i][j] = 0 //  同じ行列へのコストは当然0
			} else {
				m[i][j] = math.MaxInt64
			}
		}
	}

	// num : 行列の数. num == 1の場合は初期値0を格納ずみ
	for num := 2; num <= n; num++ {
		// s : スタート行列番号
		for s := 0; s+num <= n; s++ {
			// t : 終了行列番号
			t := s + num - 1
			// k : 仕切
			for k := s; k < t; k++ {
				m[s][t] = min(m[s][t], m[s][k]+m[k+1][t]+p[s]*p[k+1]*p[t+1])
			}
		}
	}
	fmt.Println(m[0][n-1])
}

////////////////////////////////////////////////////////////////////////////////
// ライブラリ
////////////////////////////////////////////////////////////////////////////////
func makeScanner(maxByte int) *bufio.Scanner {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Buffer(make([]uint8, 0, 8192), maxByte)
	return scanner
}
func makeWordScanner() *bufio.Scanner {
	scanner := makeScanner(8192)
	scanner.Split(bufio.ScanWords)
	return scanner
}
func eGetLine(r *bufio.Scanner) string {
	if r.Scan() {
		return r.Text()
	}
	err := r.Err()
	if err != nil {
		log.Fatal(err)
	}
	// EOF
	return ""
}
func eGetInt(r *bufio.Scanner) int {
	line := eGetLine(r)
	return eAtoi(line)
}
func eGetFields(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Fields(line)
}
func eGetInts(r *bufio.Scanner) []int {
	fields := eGetFields(r)
	ints := make([]int, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoi(fields[i])
	}
	return ints
}
func eGetChars(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Split(line, "")
}
func eAtoi(s string) int {
	n, err := strconv.Atoi(s)
	if err != nil {
		log.Fatal(err)
	}
	return n
}

type ints []int

func (s ints) String() string {
	var buf bytes.Buffer
	buf.WriteString("[")
	sep := ""
	for _, v := range s {
		buf.WriteString(fmt.Sprintf("%s%d", sep, v))
		sep = ", "
	}
	buf.WriteString("]")
	return buf.String()
}

func reverse(a ints) ints {
	r := make(ints, len(a))
	for i := 0; i < len(a); i++ {
		r[i] = a[len(a)-1-i]
	}
	return r
}
func max(a ints) (int, bool) {
	if len(a) == 0 {
		return 0, false
	}
	m := a[0]
	for _, e := range a {
		if e > m {
			m = e
		}
	}
	return m, true
}

// func min(a []int) int {
// 	m := a[0]
// 	for _, v := range a {
// 		if v < m {
// 			m = v
// 		}
// 	}
// 	return m
// }

func sum(a ints) int {
	if len(a) == 0 {
		return 0
	}
	sum := 0
	for _, e := range a {
		sum += e
	}
	return sum
}
func find(n int, a ints) int {
	for i, v := range a {
		if n == v {
			return i
		}
	}
	return -1
}

C++: #include <iostream>
#include <sstream>
#include <cstdio>
#include <cmath>
#include <cctype>
#include <string>
#include <vector>
#include <list>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <algorithm>
#include <functional>
 
using namespace std;
using ll = long long int;
#define rep(i,n) for(int i = 0; i < n; i++)
#define FOR(i, a, b)  for(int i = (a); i < (b) ; i++)

#define pb push_back
#define SORT(v,n) sort(v, v+n)
#define ALL(x) (x).begin(),(x).end()
#define debug(x) cerr << #x << ": " << x << '\n'
#define elif else if
#define itn ll
#define int ll
const int INF = 100100100;
const int MOD = (int)1e9 + 7;
const double EPS = 1e-9;
///                →,↑,←,↓,↗,↖,↙,↘
int dx[8] = { 1, 0, -1, 0, 1, -1, -1, 1 };
int dy[8] = { 0, 1, 0, -1, 1, 1, -1, -1 };
 
 static const int N = 100;

signed main() {
    ios::sync_with_stdio(false);
    int n,p[N + 1],m[N+1][N+1];
    cin>> n;
    int i;
    FOR(i,1,n+1){
        cin >> p[i-1] >> p[i];
    }
    FOR(i,1,n+1) 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] << '\n';
    return 0;
}

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

using namespace std;

static const int N=100;

int main(){
  int n,i,l,j,k,p[N+1],m[N+1][N+1];
  cin>>n;

  for(i=1;i<=n;i++){
    cin>>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]=(1<<21);
          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]);
          }
      }
   }

      cout<<m[1][n]<<endl;
      return 0;
}

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

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 <bits/stdc++.h>
#include <math.h>
#include <vector>
#include <queue>
#include <iomanip>
#include <string>
#include <algorithm>
using namespace std;
#define rep(i,n) for(int i=0;i<n;i++)
#define rep_1 (i,j,n) for(int i=j;i<n;i++)
typedef long long ll;
typedef long l;
const ll l_INF = 1010101010101010;
const int INF = 1010101010;
const int dx[] = {-1,0,1,0,-1,-1,1,1};
const int dy[] = {0,-1,0,1,1,-1,1,-1};
ll dp[110][110];
ll m[2][110];

ll solve(int x,int y){
  if(dp[x][y]!=l_INF) return dp[x][y];
  ll ans=l_INF;
  for(int i=x+1;i<=y;i++){
    ans=min(ans,solve(x,i-1)+solve(i,y)+m[0][x]*m[1][i-1]*m[1][y]);
  }
  //cout<<ans<<endl;
  return dp[x][y]=ans;
}
int main(){
  int n; cin>>n;
  rep(i,n) cin>>m[0][i]>>m[1][i];
  rep(i,n)rep(j,n) dp[i][j]=l_INF;
  rep(i,n) dp[i][i]=0;
  rep(i,n-1) dp[i][i+1]=m[0][i]*m[0][i+1]*m[1][i+1];
  cout<<solve(0,n-1)<<endl;
}

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

using namespace std;

int main(void) {
	int n;
	cin >> n;
	vector< pair<int,int> > mat(n);
	for (int i = 0; i < n; ++i) {
		cin >> mat[i].first >> mat[i].second;
	}
	vector< vector<int> > dp(n,vector<int>(n,(1 << 28)));
	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) {
			for (int j = 0; j < k; ++j) {
				dp[i][i+k] = min(dp[i][i+j]+dp[i+j+1][i+k]+(mat[i].first*mat[i+j+1].first*mat[i+k].second),dp[i][i+k]);
			}
		}
	}
	cout << dp[0][n-1] << endl;
	return 0;
}

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

using namespace std;

template <class T>
T Vec(T v) { return v; }

template <class T, class... Ts>
auto Vec(size_t l, Ts... ts) {
    return vector<decltype(Vec<T>(ts...))>(l, Vec<T>(ts...));
}

const int INF = 1 << 30;

int N;
vector<int> deg;

int rec(int l, int r) {
    static auto dp = Vec<int>(N + 1, N + 1, -1);
    if (r - l <= 1) return 0;
    if (dp[l][r] >= 0) return dp[l][r];
    dp[l][r] = INF;

    for (int p = l + 1; p < r; ++p) {
        dp[l][r] = min(dp[l][r], rec(l, p) + rec(p, r) + deg[l] * deg[p] * deg[r]);
    }
    return dp[l][r];
}

int main() {
    cin >> N;

    deg.resize(N + 1);
    for (int i = 0; i < N; ++i) {
        int r, c;
        cin >> r >> c;
        deg[i] = r;
        if (i == N - 1) deg[i + 1] = c;
    }
    cout << rec(0, N) << endl;
    return 0;
}