#include<bits/stdc++.h>//导入输出工具库 using namespace std;//规定一个范围空间 叫std

int a[110][110];

int main()//主程序的入口 { int n; cin >> n; for (int i = 1; i <= n; i++){ for (int j = 1; j <= i; j++){ cin >> a[i][j]; } } for (int i = n - 1; i >= 1; i--){ for (int j = 1; j <= i; j++){ if (a[i + 1][j] < a[i + 1][j + 1]){ a[i][j] += a[i + 1][j + 1]; }else{ a[i][j] += a[i + 1][j]; } } } cout << a[1][1] << endl; return 0; }