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;

// 総数を1000000007で割った余り
const long long mod = 1e9 + 7;

using ll  = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
#define ull unsigned long long
#define ld long double
#define vi vector<int>
#define vll vector<ll>
#define vc vector<char>
#define vs vector<string>
#define vpii vector<pii>
#define vpll vector<pll>

#define rep(i, n) for (int i = 0, i##_len = (n); i < i##_len; i++)
#define rep1(i, n) for (int i = 1, i##_len = (n); i <= i##_len; i++)
#define repr(i, n) for (int i = ((int)(n)-1); i >= 0; i--)
#define rep1r(i, n) for (int i = ((int)(n)); i >= 1; i--)

#define sz(x) ((int)(x).size())
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()

#define SORT(v, n) sort(v, v + n);
// #define SORT(v, n) stable_sort(v, v + n);
#define VSORT(v) sort(v.begin(), v.end());
#define RSORT(x) sort(rall(x));
#define pb push_back
#define mp make_pair

#define INF (1e9)
#define PI (acos(-1))
#define EPS (1e-7)

ull gcd(ull a, ull b) { return b ? gcd(b, a % b) : a; }
ull lcm(ull a, ull b) { return a / gcd(a, b) * b; }

static const int N = 100;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    // cout << fixed << setprecision(5);

    int n;
    cin >> n;
    int p[N + 1], m[N + 1][N + 1];
    rep1(i, n) { cin >> p[i - 1] >> p[i]; }
    rep1(i, n) 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>
using namespace std;

const int INF = 1 << 30;
int n;
vector<int> r, c;
vector<vector<int>> dp;

int dfs(int a, int b) {
    if (dp[a][b] != INF) return dp[a][b];
    if (a + 1 == b) return dp[a][b] = 0;
    int res = INF;
    for (int k = a + 1; k < b; ++k) {
        res = min(res, dfs(a, k) + dfs(k, b) + r[a] * r[k] * c[b - 1]);
    }
    return dp[a][b] = res;
}

int main() {
    cin >> n;
    r.resize(n);
    c.resize(n);
    for (int i = 0; i < n; ++i) {
        cin >> r[i] >> c[i];
    }
    dp.resize(n + 1, vector<int>(n + 1, INF));
    cout << dfs(0, n) << endl;
}

C++: #include <iostream>
#include <string>
#include <sstream>
#include <list>
#include <stack>
#include <queue>
#include <algorithm>
#include <utility>
#include <vector>
#include <map>
#include <cstring>
#include <cstdio>
#include <cmath>
#include <climits>
 
using namespace std;
 
int f(const int);
 
int main()
{
    int N;
    pair<int,int> data[100];
    vector<vector<int> > vdata(100,vector<int>(100,INT_MAX));
    cin>>N;
    for(int i=0;i<N;i++){
        cin>>data[i].first>>data[i].second;
    }
    vdata[0][0]=0;
    for(int j=1;j<N;j++){
        vdata[j][j]=0;
        for(int i=j-1;i>=0;i--){
            for(int k=i+1;k<=j;k++){
                int c=vdata[i][k-1]+vdata[k][j]+data[i].first*data[k].first*data[j].second;
                if(c<vdata[i][j]){
                    vdata[i][j]=c;
                }
            }
        }
    }
    cout<<vdata[0][N-1]<<endl;
}

C++: #include <iostream>

using namespace std;

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

    int dp[101][101];
    int N[101];
    for (int i = 1; i <= n; ++i) {
        cin >> N[i- 1] >> N[i];
    }

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

    for (int len = 2; len <= n ; ++len) {
        for (int i = 1; i <= n - len + 1; ++i) {
            int j = i + len - 1;
            dp[i][j] = (1 << 21);
            for (int k = i; k <= j - 1; ++k) {
                dp[i][j] = min(dp[i][j], dp[i][k] + dp[k + 1][j] + N[i - 1] * N[k] * N[j]);
            }
        }
    }

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

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

typedef long long lli;

const lli INF = 1LL << 59;
const int N = 1000;

int n;
vector<lli> v;

void solve(){
  lli dp[N][N];
  fill(dp[0],dp[N],INF);
  
  for(int i=0;i<=n;i++) dp[i][i] = 0;
  for(int i=2;i<=n;i++){
    for(int j=0;j+i-1<n;j++){
      int next = j + i - 1;
      for(int k=j;k<next;k++){
        dp[j][next] = min(dp[j][next], dp[j][k] + dp[k+1][next] + v[j] * v[k+1] * v[next+1]);
      }
    }
  }

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

int main(){
  while(cin >> n){
    v.clear();
    for(int i=0;i<n;i++) {
      int a,b;
      cin >> a >> b;
      if(i == 0) v.push_back(a);
      v.push_back(b);
    }
    solve();
  }
}

C++: #include <iostream>
#include <string.h>
using namespace std;

int n, a[100], v[101];
long sum, m = 1000000000;
bool f[100], g[100];

void permsum(int p) {
	if (p == n - 1) {
		sum = 0;
		memset(g, 0, 100);
		for (int i = 0; i < n - 1; i++) {
			g[a[i]] = 1;
			int u = 1, w = 1;
			while (g[a[i] - u])
				u++;
			while (g[a[i] + w])
				w++;
			sum += v[a[i] - u] * v[a[i]] * v[a[i] + w];			
		}
		if (m > sum)
			m = sum;
	}
	else {
		for (int j = 0; j < n - 1; j++) {
			if (!f[j]) {
				a[p] = j + 1;
				f[j] = 1;
				permsum(p + 1);
				f[j] = 0;
			}
		}
	}
}

int main()
{
	cin >> n;

	for (int i = 0; i < n; i++)
		cin >> v[i] >> v[i + 1];

	permsum(0);

	cout << m << endl;

	return 0;
}