#include <iostream>#include <stdio.h>#include <string.h>#include <algorithm>#include <queue>#include <math.h>#define N 400#define inf 0x3f3f3f3ftypedef int ll;using namespace std;int a[N][N],dp[N][N];int main(){    int n;    while(scanf("%d",&n)!=EOF)    {        for(int i=1; i<=n; i++)        {            for(int j=1; j<=i; j++)                scanf("%d",&a[i][j]);        }        for(int i=1; i<=n; i++)        {            dp[n][i]=a[n][i];        }        for(int i=n-1; i>=1; i--)        {            for(int j=1; j<=i; j++)            {                dp[i][j]=max(a[i][j]+dp[i+1][j],a[i][j]+dp[i+1][j+1]);            }        }        printf("%d\n",dp[1][1]);    }    return 0;}