Contest1234/B.cpp

//
// Created by liuhuan on 18-11-7.
//
#include <bits/stdc++.h>

using namespace std;
#define Max 101

int D[Max][Max];
int num;
int MaxSum(int num){
    for(int i = num - 1; i >= 1; i --)
        for(int j = 1; j <= i; j ++){
            D[i][j] = max(D[i+1][j],D[i+1][j+1]) + D[i][j];
        }
    return D[1][1];
}
int main()
{
    cin >> num;
    for(int i = 1; i <= num; i ++)
        for(int j = 1; j <= i; j ++)
            cin >> D[i][j];
    cout << MaxSum(num) << endl;
    return 0;
}