#include <fstream>
using namespace std;
#define dim 1000
int mat[dim][dim],v[dim];
int main()
{
	ifstream fin("podm.in");
	ofstream fout("podm.out");
	int n, i,j;
	
	fin>>n;
	
	for(i=1;i<=n+1;++i)
		fin>>v[i];
	
	for(i=1;i<n;++i)
		mat[i][i+1]=v[i]*v[i+1]*v[i+2];
	
	int	k;
	
	for(k=1;k<=n-2;++k)
	{
		j=k+2;
			for(i=k;i>=1;--i)
			{
		
				mat[i][j]=min(mat[i][j-1]+v[1]*v[j]*v[j+1],mat[i+1][j]+v[1]*v[2]*v[j+1]);
				
			}	
		
	}
	
	fout<<mat[1][n];
	
	return 0;
}