1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
#include <bits/stdc++.h>
using namespace std;
typedef long long lld;
typedef unsigned long long llu;
typedef double lf;
typedef long double llf;
typedef pair<int,int> pii;
#define pb push_back
#define mp make_pair
#define dd second
#define ff first
#define sz size()
#define For(i,s,a) for(lld i=(lld)s;i<(lld)a;++i)



int32_t main(void){
	int a,b;
	scanf("%d%d", &a,&b);
	int wyn = 999999999, g;
	For(i,1,a+1){
		For(j,1,i+1){
			scanf("%d", &g);
			if(j * (i+1-j) <= b)
				wyn = min(wyn,g);
		}
	}
	printf("%d",wyn);
}