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 <bits/stdc++.h>
#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,n) for(int i=0;i < (n);i++)
#define ALL(obj) (obj).begin(),(obj).end()
using namespace std;

const long long INF = 1LL << 60;
const int MOD = (int)1e9 + 7;
typedef long long ll;
//約数列挙
vector<long long> divisor(long long n) {
    vector<long long> ret;
    for (long long i = 1; i * i <= n; i++) {
        if (n % i == 0) {
            ret.push_back(i);
            if (i * i != n) ret.push_back(n / i);
        }
    }
    //sort(ret.begin(), ret.end()); // 昇順に並べる
    return ret;
}
vector<int> dx={1,0,-1,0};vector<int> dy={0,-1,0,1};

signed main () {
    int m;scanf("%d",&m);
    vector<vector<int>> cost(m+1,vector<int>(m+1));
    vector<int> p(m+1);
    FOR(i,1,m+1){
        int a,b;scanf("%d %d",&a,&b);
        p[i-1] = a;p[i]=b;
    }
    REP(i,m)cost[i][i] = 0;
    int min_cost;
    for (int l = 2; l <= m; l++) {  // 行列の個数
        for (int i = 1; i <= m - l + 1; i++) {
            int j = i + l - 1;
            for (int k = i; k < j; k++) {
                if (k == i) min_cost = cost[i][k] + cost[k+1][j] + p[i-1] * p[k] * p[j];
                else min_cost = min(min_cost, cost[i][k] + cost[k+1][j] + p[i-1] * p[k] * p[j]);
            }
            cost[i][j] = min_cost;
        }
    }
    cout << cost[1][m] << endl;
}

C++: #include<iostream>
#include<map>
#include<vector>
#include<algorithm>
#include<cmath>
#include<climits>
#include<ctime>
#include<cstring>
#include<numeric>

#define ALL(v) (v).begin(),(v).end()
#define REP(i,p,n) for(int i=p;i<(int)(n);++i)
#define rep(i,n) REP(i,0,n)
#define dump(a) (cerr << #a << "=" << (a) << endl)
#define DUMP(list) cout << "{ "; for(auto nth : list){ cout << nth << " "; } cout << "}" << endl;

using namespace std;

struct matrix {
	int r, c;
	matrix(int r_ = 0, int c_ = 0) : r(r_), c(c_) {}
};

const int INF = 100000000;
vector<vector<int>> dp;

int mul(int r1, int rm, int c2) { return r1 * c2 * rm; }

int main() {
	int N;
	cin >> N;
	int R, C;
	vector<matrix> mats(N);	
	dp.assign(N+1, vector<int>(N+1, INF)); //[l, r)
	rep(i, N) {
		cin >> R >> C;
		mats[i] = matrix(R, C);
	}

	for(int len = 1; len < N+1; ++len) {
		for(int l = 0; l <= N-len; ++l) {
			int r = l + len;	
			if(l+1 == r) {
				dp[l][r] = 0;	
				continue;	
			}		
			for(int m = l+1; m < r; ++m) {	
				int r1 = mats[l].r;
				int rm = mats[m].r;
				int c2 = mats[r-1].c;
				dp[l][r] = min(dp[l][m] + dp[m][r] + mul(r1, rm, c2), dp[l][r]);
			}
		}
	}
	cout << dp[0][N] << endl;
	return 0;
}

C++: #include <iostream>
#include <algorithm>
using namespace std;
static const int N = 101;
int main()
{
    int n;
    int p[N],m[N][N];
    cin>>n;
    for (int i = 1; i <= n; i++)
    {
        cin>>p[i-1]>>p[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<cstdio>
#include<algorithm>
using namespace std;
#define MAX 100
int p[MAX+1] = {0};
int m[MAX+1][MAX+1] = {0};

int main()
{
	int n;
	int a,b;
	scanf("%d" ,&n);
	for(int i=0; i<n; i++)
	{
		scanf("%d%d", &a, &b);
		if(i == 0) p[0] = a;
		p[i+1] = b;
	}

	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 << 30);
			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]);
		}
	}

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

	return 0;


}

C++: #include <bits/stdc++.h>
#define r(i,n) for(int i=0;i<n;i++)
#define int long long
using namespace std;
int dp[111][111],n,L[111],R[111];

int dfs(int l,int r){
	if(dp[l][r]!=-1)return dp[l][r];
	if(l==r)return 0;
	int res=1e17;
	for(int i=l;i<r;i++){
		res=min(res,dfs(l,i)+dfs(i+1,r)+L[l]*R[i]*R[r]);
	}
	return dp[l][r]=res;
}

signed main(){
	memset(dp,-1,sizeof(dp));
	cin>>n;
	r(i,n)cin>>L[i]>>R[i];
	dfs(0,n-1);
	cout<<dp[0][n-1]<<endl;
}