import java.util.*;


public class Main_yukicoder168 {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int n = sc.nextInt();

        int[] x = new int[n];
        int[] y = new int[n];
        for (int i = 0; i < n; i++) {
        	x[i] = sc.nextInt();
        	y[i] = sc.nextInt();
        }

        List<Tri> p = new ArrayList<>();
        for (int i = 0; i < n; i++) {
        	for (int j = i + 1; j < n; j++) {
        		long d = (long)(x[i] - x[j]) * (x[i] - x[j]) + (long)(y[i] - y[j]) * (y[i] - y[j]);
        		p.add(new Tri(i, j, d));
        	}
        }
        Collections.sort(p);

        UnionFind uf = new UnionFind(n);
        long min = Long.MAX_VALUE;
        for (Tri e : p) {
        	uf.union(e.i, e.j);
        	if (uf.same(0, n - 1)) {
        		min = e.d;
        		break;
        	}
        }

        long l = 0;
        long r = 200_000_000;
        for (int i = 0; i < 100; i++) {
        	long mid = l + (r - l) / 2;

        	long tmp = (mid * 10) * (mid * 10) - min;
        	if (tmp >= 0) {
        		r = mid;
        	} else {
        		l = mid;
        	}
        }

        System.out.println(r * 10);

        sc.close();
    }

    private static class Tri implements Comparable<Tri> {
    	int i;
    	int j;
    	long d;

    	Tri(int i, int j, long d) {
    		this.i = i;
    		this.j = j;
    		this.d = d;
    	}

		@Override
		public int compareTo(Tri o) {
			return Long.compare(this.d, o.d);
		}
    }

	@SuppressWarnings("unused")
	private static class UnionFind {
		int[] parent;
		int[] rank;

		UnionFind(int n) {
			parent = new int[n];
			rank = new int[n];
			for (int i = 0; i < n; i++) {
				parent[i] = i;
				rank[i] = 0;
			}
		}

		int find(int x) {
			if (parent[x] == x) {
				return x;
			} else {
				return parent[x] = find(parent[x]);
			}
		}

		boolean same(int x, int y) {
			return find(x) == find(y);
		}

		void union(int x, int y) {
			x = find(x);
			y = find(y);
			if (x != y) {
				if (rank[x] > rank[y]) {
					parent[y] = x;
				} else {
					parent[x] = y;
					if (rank[x] == rank[y]) {
						rank[y]++;
					}
				}
			}

			return;
		}

		// 異なる集合の数
		int count() {
			int ret = 0;
			for (int i = 0; i < parent.length; i++) {
				if (find(i) == i) {
					ret++;
				}
			}

			return ret;
		}
	}
}