#include<iostream>
#include<cstdio>
using namespace std;
const int N = 1010;
int n,f[N][N];
int main(){
	scanf("%d",&n);
	for(int i = 1;i <= n;i++){
		for(int j = 1;j <= i;j++){
			scanf("%d",&f[i][j]);
		}
	}
	for(int i = 2;i <= n;i++){
		for(int j = 1;j <= i;j++){
			f[i][j] = max(f[i-1][j-1],f[i-1][j]);
		}
	}
	int maxx = -1;
	for(int i = 1;i <= n;i++){
		if(f[N][i] > maxx){
			maxx = f[N][i];
		}
	}
	cout<<maxx<<endl;
	
	return 0;
}

样例输出 1 怎么办啊QWQ