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 <cassert>
// #include <algorithm>
#include <iostream>
#include <vector>
#include <climits>

struct TSize
{
    int r;
    int c;
    TSize() : r(0), c(0) {}
    TSize(int Ar, int Ac)
     : r(Ar), c(Ac)
    {}
};

class TMcmSolver
{
    typedef std::vector<std::vector<int> > TMatrix;
    TMatrix FMemo;
    const std::vector<TSize>& FChain;

    static int Count(const TSize& Left, const TSize& Right)
    {
        return Left.r * Right.c * Left.c;
    }
    int Solve(int s, int l)
    {
        assert(s <= l);
        if(s == l) return 0;
        if(FMemo[s][l] != 0) return FMemo[s][l];
        if(s + 1 == l){
            FMemo[s][l] = Count(FChain[s], FChain[l]);
        }else{
            int min = INT_MAX;
            for(int i = s; i < l; ++i){
                int c = Solve(s, i) + Count(TSize(FChain[s].r, FChain[i].c), TSize(FChain[i+1].r, FChain[l].c)) + Solve(i+1, l);
                min = std::min(min, c);
            }
            FMemo[s][l] = min;
        }
        // std::cout << "Solve! [" << s << "], [" << l << "]" << std::endl; 
        return FMemo[s][l];
    }
public:
    TMcmSolver(const std::vector<TSize>& Chain)
     : FChain(Chain)
    {
        FMemo.resize(Chain.size());
        for(std::size_t i = 0; i < FMemo.size(); ++i){
            FMemo[i].resize(Chain.size(), 0);
        }
    }
    int Answer()
    {
        return Solve(0, FMemo.size()-1);
    }
    void Print()const
    {
        for(std::size_t s = 0; s < FMemo.size(); ++s){
            for(std::size_t l = 0; l < FMemo[0].size(); ++l){
                std::cout << FMemo[s][l] << '\t';
            }
            std::cout << '\n';
        }
    }
};

int main()
{
    int n;
    std::cin >> n;
    if(n == 1){
        std::cout << 0 << std::endl;
        return 0;
    }
    std::vector<TSize> Chain(n);
    for(int i = 0; i < n; ++i){
        std::cin >> Chain[i].r >> Chain[i].c;
    }
    TMcmSolver Solver(Chain);
    
    std::cout << Solver.Answer() << std::endl;
    // Solver.Print();
    return 0;
}

C++: #include <cstdio>
#include <cstring>
#include <cstdlib>
#include <vector>
using namespace std;


#define min(a, b) ((a) < (b) ? (a) : (b))

int N;
const int MAX_N = 110;
const int INF = 0x3fffffff;
int A[MAX_N];
int B[MAX_N];
int dp[MAX_N][MAX_N];

void init() {
    scanf("%d", &N);
    for(int i = 0; i < N; ++i)
        scanf("%d%d",&A[i], &B[i]);
    for(int i = 0 ;i < N; ++i)
        for(int j = 0; j < N; ++j)
            dp[i][j] = INF;
    for(int i = 0; i < N; ++i)
        dp[i][i] = 0;
}

int solve() {
    for(int k = 1; k < N; ++k) {
        for(int i = 0; i < N - k; ++i) {
            for(int j = i; j < i + k; ++j) {
                printf("i = %d j = %d k = %d\n", i, j, k);
                int sz = A[i] * B[j] * B[i + k];
                dp[i][i + k] = min(dp[i][i + k],dp[i][j] + dp[j+1][i + k] + sz);
            }
        }
    }
    // for(int i = 0; i < N; ++i) {                                                                                                                                              
    //  for(int j = 0; j < N; ++j)                                                                                                                                               
    //      printf("%d ", dp[i][j]);                                                                                                                                             
    //  printf("\n");                                                                                                                                                            
    // }                                                                                                                                                                         
    return dp[0][N - 1];
}

int main() {
    init();
    printf("%d\n", solve());
    return 0;
}