#include <iostream>
using namespace std;
int n,i,j,a[100][100];
int solve(int x,int y)
{
int u,v;
if(x==n) returna[x][y];
u=solve(x+1,y);
v=solve(x+1,y+1);
if(u>v)return a[x][y]+u;
else returna[x][y]+v;
}
int main()
{
cin>>n;
for(i=1;i<=n;i++)
for(j=1;j<=i;j++)cin>>a[i][j];
cout<<solve(1,1)<<endl;
return 0;
}输入：
5
2
-1 4
2 -1 -2
-1 6 4 0
3 2 -1 5 8
输出：____