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<cstdio>
#include<string>
#include<algorithm>

#define X 100000001

using namespace std;

int RE[101][101];
int *p;

int rec(int r, int c){
  int M=X;
  int num=c-r;
  int i;
  for(i=0;i<num;i++)M=min(M, RE[r][r+i]+RE[r+i+1][c]+p[r-1]*p[r+i]*p[c]);
  return M;
}

int main(){
  int N;
  cin>>N;
  int i, j;
  for(i=1;i<=N;i++)RE[i][i]=0;
  p=(int *)malloc(sizeof(int)* (N+1));

  cin>>p[0];
  cin>>p[1];
  int bb;
  for(i=2;i<=N;i++){
    cin>>bb;
    cin>>p[i];
  }

  for(i=1;i<N;i++)RE[i][i+1]=p[i-1]*p[i]*p[i+1];

  for(j=0;j<=N-3;j++){
    for(i=3+j;i<=N;i++){
      RE[i-2-j][i]=rec(i-2-j,i);
    }
  }

  cout<<RE[1][N]<<endl;

  return 0;
}

C++: #include <iostream>
using namespace std;
int n, a[111], b[111], dp[111][111];
int main() {
	cin >> n;
	for(int i = 0; i < n; i++) cin >> a[i] >> b[i];
	for(int i = 2; i <= n; i++) {
		for(int j = 0; j <= n - i; j++) {
			int l = j, r = j + i; // [l, r)
			dp[l][r] = 999999999;
			for(int k = l + 1; k < r; k++) {
				dp[l][r] = min(dp[l][r], dp[l][k] + dp[k][r] + a[l] * b[k] * b[r]);
			}
		}
	}
	cout << dp[0][n] << endl;
}

C++: #define _USE_MATH_DEFIMES
#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <cctype>
#include <climits>
#include <clocale>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <ctime>
#include <deque>
#include <fstream>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <regex>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <tuple>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

const int MOD = 1'000'000'007;
const int INF = 1'000'000'000; //1e9
const int NIL = -1;
const long long LINF = 1'000'000'000'000'000'000; // 1e18
const long double EPS = 1E-10;

template<class T, class S> inline bool chmax(T &a, const S &b){
    if(a < b){
        a = b; return true;
    }
    return false;
}
template<class T, class S> inline bool chmin(T &a, const S &b){
    if(b < a){
        a = b; return true;
    }
    return false;
}








int main(){
    int n; std::cin >> n;
    std::vector<int> r(n), c(n);
    for(int i(0); i < n; ++i) std::cin >> r[i] >> c[i];
    //dp[i][j] := iからjまでの計算に必要な回数
    std::vector<std::vector<int>> dp(n, std::vector<int>(n, 0));
    for(int d(1); d < n; ++d){
        for(int i(0), i_len(n - d); i < i_len; ++i){
            int j(i + d);
            dp[i][j] = INF;
            for(int k(i); k < j; ++k){
                chmin(dp[i][j], dp[i][k] + dp[k+1][j] + r[i]*c[k]*c[j]);
            }
        }
    }
    std::cout << dp[0][n-1] << std::endl;
    return 0;
}

C++: // ALDS 1_10_B
#include<cstdio>
#include<cstring>
#include<vector>
#define rep(i,a) for( int i = 0; i != (a); ++i )
#define repi(i,a,b) for( int i = (a); i != (b); ++i )

const int INF = 1<<28;

int n;
std::vector<int> r(100);
std::vector<std::vector<int> > dp( 100, std::vector<int>( 100, INF ) );

int main()
{
	scanf( "%d", &n );
	rep( i, n )
		scanf( "%d%d", &r[i], &r[i+1] );

	rep( i, n )
		dp[i][i] = 0;

	repi( k, 1, n ) rep( i, n-k ) repi( j, i, i+k )
		dp[i][i+k] = std::min( dp[i][i+k], dp[i][j]+dp[j+1][i+k]+r[i]*r[j+1]*r[i+k+1] );	

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

	return 0;
}

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

using namespace std;

int main()
{
    int n;
    cin >> n;
    vector<pair<int, int>> v;
    for (int i = 0; i < n; ++i) {
        int r, c;
        cin >> r >> c;
        v.emplace_back(r, c);
    }

    vector<vector<int>> dp(n, vector<int>(n, numeric_limits<int>::max()));

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

    auto cost = [&v](int i, int k, int j) {
        return v[i].first * v[k].second * v[j].second;
    };

    // auto p = [&dp, n] {
    //    for (int i = 0; i < n; ++i) {
    //        for (int j = 0; j < n; ++j) {
    //            cout << dp[i][j] << ' ';
    //        }
    //        cout << endl;
    //    }
    //    cout << endl;
    //};
    for (int l = 2; l <= n; ++l) {
        for (int i = 0; i < n - l + 1; ++i) {
            int j = i + l - 1;
            for (int k = i; k < j; ++k) {
                dp[i][j] =
                    min(dp[i][j], dp[i][k] + dp[k + 1][j] + cost(i, k, j));
            }
        }
    }
    cout << dp[0][n - 1] << endl;
}