Go: package main

import (
	"bufio"
	"fmt"
	"math"
	"os"
	"strconv"
)

type Matrix struct {
	r int // num of row
	c int // num of column
}

type Range struct {
	start int // index, inclusive
	end   int // index, inclusive
}

func (r Range) length() int {
	return r.end - r.start + 1
}

func calcMultiplication(x, y Matrix) (Matrix, int) {
	if x.c != y.r {
		panic("cannnot calculate")
	}
	return Matrix{x.r, y.c}, x.r * y.c * x.c
}

func calcMinMatrixChainMultiplication(matrices []Matrix, r Range, memo map[Range]int) (Matrix, int) {
	if v, ok := memo[r]; ok {
		return Matrix{matrices[r.start].r, matrices[r.end].c}, v
	}
	if r.length() == 0 {
		panic("must not be empty")
	} else if r.length() == 1 {
		return matrices[r.start], 0
	}

	var minCount int = math.MaxInt32

	for i := 0; i < r.length()-1; i++ {
		formerRange := Range{r.start, r.start + i}
		latterRange := Range{r.start + i + 1, r.end}
		matF, countF := calcMinMatrixChainMultiplication(matrices, formerRange, memo)
		matL, countL := calcMinMatrixChainMultiplication(matrices, latterRange, memo)
		_, countFL := calcMultiplication(matF, matL)
		count := countF + countL + countFL
		if count < minCount {
			minCount = count
		}
	}
	memo[r] = minCount
	return Matrix{matrices[r.start].r, matrices[r.end].c}, minCount
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	n, _ := nextInt(sc)
	matrices := make([]Matrix, n)
	for i := 0; i < n; i++ {
		r, _ := nextInt(sc)
		c, _ := nextInt(sc)
		matrices[i] = Matrix{r, c}
	}
	memo := make(map[Range]int)
	_, resultCount := calcMinMatrixChainMultiplication(matrices, Range{0, len(matrices) - 1}, memo)
	fmt.Println(resultCount)
}

func nextInt(sc *bufio.Scanner) (int, error) {
	sc.Scan()
	return strconv.Atoi(sc.Text())
}

C++: #include <iostream>
#include <algorithm>
#include <vector>
#include <deque>
#include <queue>
#include <list>
#include <stack>
#include <string>
#include <tuple>
#include <functional>
#include <numeric>
#include <cmath>
#include <iomanip>
#include <map>
#include <random>
#include <cstdlib>
#define INT_MAX 2147483647
#define INT_MIN -2147483646
#define Loop(i, n) for(int i = 0; i < (int)n; i++)
#define Loop1(i, n) for(int i = 1; i <= (int)n; i++)
#define Loopr(i, n) for(int i = (int)n - 1; i >= 0; i--)
#define Loopr1(i, n) for(int i = (int)n; i >= 1; i--)
using namespace std;
typedef long long int ll;

ll memo[105][105];
int r[105], c[105];

ll func(int a, int b) {
	if (b - a == 0) { 
		memo[a][b] = 0;
	}
	else {
		ll m = INT_MAX;
		for (int k = a;k < b;k++) {
			m = min(m, func(a, k) + func(k + 1, b) + r[a] * c[k] * c[b]);
		}
		memo[a][b] = m;
	}
	return memo[a][b];
}

int main() {
	int n;
	cin >> n;
	Loop(i, n) {
		cin >> r[i] >> c[i];
	}
	cout << func(0, n - 1) << endl;
}

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

typedef long long ll;
#define inf 1e9+7

int n;
ll dp[102][102];
ll p[102];

void init(){
    for(int i=0;i<=n;i++){
        for(int j=0;j<=n;j++){
            dp[i][j]=inf;
        }
        dp[i][i]=0;
    }
}

void cal(int l, int r){
    if(l>=r)return;
    if(dp[l][r]<inf)return;
    for(int k=l;k<r;k++){
        cal(l,k);
        cal(k+1,r);
        dp[l][r] = min(dp[l][r], dp[l][k]+dp[k+1][r]+p[l]*p[k+1]*p[r+1]);
    }
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);

    cin >> n;
    init();
    cin >> p[0] >> p[1];
    ll a,b;
    for(int i=1;i<n;i++){
        cin >> a >> b;
        p[i+1]=b;
    }
    cal(0,n-1);
    cout << dp[0][n-1] << endl;
    return 0;
}

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

#define rep(i,n) for(int i=0;i<(n);i++)
using namespace std;
const int INF=1e9;
int n;
int r[102],c[102];
int p[102];

int dp[102][102];
// [i,j)
int dfs(int i,int j) {
    //cout<<i<<", "<<j<<endl;
    if(dp[i][j]!=-1) return dp[i][j];
    if(j-i==1) return r[i]*c[i]*c[j-1];
    if(i==j) return 0;
    int ret=INF;
    for(int k=i+1;k<j;k++) {
        //ret=min(ret,dfs(i,k)+dfs(k,j)+r[i]*c[k]*c[j-1]);
        ret=min(ret,dfs(i,k)+dfs(k,j)+p[i]*p[k]*p[j]);
    }

    return dp[i][j]=ret;
}

int main() {
    memset(dp,-1,sizeof(dp));
    cin>>n;
    //rep(i,n) cin>>r[i]>>c[i];
    rep(i,n+1) if(i) cin>>p[i-1]>>p[i];
    cout<<dfs(0,n)<<endl;
    return 0;
}

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

//#define int long long
typedef long long ll;

typedef unsigned long long ul;
typedef unsigned int ui;
const ll mod = 1000000007;
const ll INF = mod * mod;
const int INF_N = 1e+9;
typedef pair<int, int> P;
#define stop char nyaa;cin>>nyaa;
#define rep(i,n) for(int i=0;i<n;i++)
#define per(i,n) for(int i=n-1;i>=0;i--)
#define Rep(i,sta,n) for(int i=sta;i<n;i++)
#define rep1(i,n) for(int i=1;i<=n;i++)
#define per1(i,n) for(int i=n;i>=1;i--)
#define Rep1(i,sta,n) for(int i=sta;i<=n;i++)
#define all(v) (v).begin(),(v).end()
typedef pair<ll, ll> LP;
typedef long double ld;
typedef pair<ld, ld> LDP;
const ld eps = 1e-12;
const ld pi = acos(-1.0);
//typedef vector<vector<ll>> mat;
typedef vector<int> vec;

//繰り返し二乗法
ll mod_pow(ll a, ll n, ll m) {
	ll res = 1;
	while (n) {
		if (n & 1)res = res * a%m;
		a = a * a%m; n >>= 1;
	}
	return res;
}

struct modint {
	ll n;
	modint() :n(0) { ; }
	modint(ll m) :n(m) {
		if (n >= mod)n %= mod;
		else if (n < 0)n = (n%mod + mod) % mod;
	}
	operator int() { return n; }
};
bool operator==(modint a, modint b) { return a.n == b.n; }
modint operator+=(modint &a, modint b) { a.n += b.n; if (a.n >= mod)a.n -= mod; return a; }
modint operator-=(modint &a, modint b) { a.n -= b.n; if (a.n < 0)a.n += mod; return a; }
modint operator*=(modint &a, modint b) { a.n = ((ll)a.n*b.n) % mod; return a; }
modint operator+(modint a, modint b) { return a += b; }
modint operator-(modint a, modint b) { return a -= b; }
modint operator*(modint a, modint b) { return a *= b; }
modint operator^(modint a, int n) {
	if (n == 0)return modint(1);
	modint res = (a*a) ^ (n / 2);
	if (n % 2)res = res * a;
	return res;
}

//逆元(Eucledean algorithm)
ll inv(ll a, ll p) {
	return (a == 1 ? 1 : (1 - p * inv(p%a, a)) / a + p);
}
modint operator/(modint a, modint b) { return a * modint(inv(b, mod)); }

const int max_n = 1 << 18;
modint fact[max_n], factinv[max_n];
void init_f() {
	fact[0] = modint(1);
	for (int i = 0; i < max_n - 1; i++) {
		fact[i + 1] = fact[i] * modint(i + 1);
	}
	factinv[max_n - 1] = modint(1) / fact[max_n - 1];
	for (int i = max_n - 2; i >= 0; i--) {
		factinv[i] = factinv[i + 1] * modint(i + 1);
	}
}
modint comb(int a, int b) {
	if (a < 0 || b < 0 || a < b)return 0;
	return fact[a] * factinv[b] * factinv[a - b];
}
using mP = pair<modint, modint>;

int dx[4] = { 0,1,0,-1 };
int dy[4] = { 1,0,-1,0 };


ll p[105], dp[105][105];

void solve() {
    int n; cin >> n;
    rep1(i, n) cin >> p[i-1] >> p[i];

    Rep1(i, 0, n)Rep1(j, 0, n){
        if(i == j) dp[i][j] = 0;
        else dp[i][j] = INF;
    }

    Rep1(l, 2, n){
        Rep1(i, 1, n-l+1){
            int j = i + l - 1;
            Rep(k, i, j){
                dp[i][j] = min(dp[i][j], dp[i][k] + dp[k+1][j] + p[i-1]*p[k]*p[j]);
            }
        }
    }

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

signed main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  //cout << fixed << setprecision(10);
  //init_f();
  //init();
  //int t; cin >> t; rep(i, t)solve();
  solve();
//   stop
    return 0;
}