from math import hypot,inf from decimal import * getcontext().prec = 20 def dist(x1,y1,x2,y2): return Decimal(hypot(abs(y2-y1),abs(x2-x1))) n = int(input()) coors = [] dists = [inf for i in range(n)] for i in range(n): x,y = map(int,input().split()) for j in range(i): d = dist(coors[j][0],coors[j][1],x,y) dists[i] = min(dists[i],d) dists[j] = min(dists[j],d) coors.append((x,y)) print(f'{max(dists)/2:.20f}')