include[HTML_REMOVED]
using namespace std;
int array[1000][1000];
int main()
{
int n;
while (cin >> n) {
int i, j;
int max= 0;
for (i = 0; i < n; i) {
for (j = 0; j <= i; j)
cin >> array[i][j];
}
for (i=n-2; i>=0;i–) {
for (j=0; j <= i; j++) {
max=array[i + 1][j];
if (max<array[i + 1][j + 1]) max=array[i + 1][j + 1];
array[i][j]+= max;
}
}
cout<<array[0][0]<< endl;
}
return 0;
}