import sys from itertools import permutations from heapq import * from math import acos input = lambda :sys.stdin.readline().rstrip() mi = lambda :map(int,input().split()) li = lambda :list(mi()) def solve(N,H,point): def calc_min(a,b,c): if a == 0: return 0 t = -b/(2*a) return a*t*t+b*t+c arg = [] for i in range(N): x,y = point[i] r = ((y-H/2)**2 + x**2)**.5 arg.append(acos((H/2-y)/r)) idx = [i for i in range(N)] idx.sort(key=lambda i:arg[i]) i_to_pos = [-1] * N for i in range(N): i_to_pos[idx[i]] = i X_idx = [i for i in range(N)] X_idx.sort(key=lambda i:point[i][0]) ans = 10**100 for i in range(N+1): up = [idx[j] for j in range(i,N)] down = [idx[j] for j in range(i)] fp,fq,fr = 0,0,0 gp,gq,gr = 0,0,0 for j in up: x,y = point[j] gp += x*x gq += 2 * x * (-y) gr += y*y for j in down: x,y = point[j] fp += x*x fq += 2 * x * (H-y) fr += (H-y) * (H-y) tmp = calc_min(fp,fq,fr) + calc_min(gp,gq,gr) ans = min(ans,tmp) for j in X_idx: x,y = point[j] if i <= i_to_pos[j]: gp -= x*x gq -= 2 * x * (-y) gr -= y*y fp += x*x fq += 2 * x * (H-y) fr += (H-y) * (H-y) else: gp += x*x gq += 2 * x * (-y) gr += y*y fp -= x*x fq -= 2 * x * (H-y) fr -= (H-y) * (H-y) tmp = calc_min(fp,fq,fr) + calc_min(gp,gq,gr) ans = min(ans,tmp) return ans def brute(N,H,point): def calc(f,g): res = 0 a,b,c = 0,0,0 for i in f: x,y = point[i] a += x*x b += 2*x*(H-y) c += (H-y)*(H-y) if a!=0: t = (-b/(2*a)) res += a * t * t + b * t + c a,b,c = 0,0,0 for i in g: x,y = point[i] a += x*x b -= 2 * x * y c += y*y if a!=0: t = (-b/(2*a)) res += a * t * t + b * t + c return res ans = 10**100 for S in range(1<>i & 1] g = [i for i in range(N) if S>>i & 1 == 0] ans = min(ans,calc(f,g)) #print(calc(f,g),f,g) return ans import random while False: N = random.randint(3,10) H = random.randint(1,10) point = [] for i in range(N): x,y = [random.randint(1,10) for _ in range(2)] point.append((x,y)) #N,H = 3,10 #point = [(4,7),(2,7),(4,5)] res = solve(N,H,point) exp = brute(N,H,point) if abs(res-exp) > 10**-2: print("WA") print(N) print(H) for x,y in point: print(x,y) print("res:",res) print("exp:",exp) exit() else: print("AC") N = int(input()) H = int(input()) point = [tuple(mi()) for i in range(N)] print(solve(N,H,point))