import sys def input(): return sys.stdin.readline().strip() def list2d(a, b, c): return [[c] * b for i in range(a)] def list3d(a, b, c, d): return [[[d] * c for j in range(b)] for i in range(a)] def list4d(a, b, c, d, e): return [[[[e] * d for j in range(c)] for j in range(b)] for i in range(a)] def ceil(x, y=1): return int(-(-x // y)) def INT(): return int(input()) def MAP(): return map(int, input().split()) def LIST(N=None): return list(MAP()) if N is None else [INT() for i in range(N)] def Yes(): print('Yes') def No(): print('No') def YES(): print('YES') def NO(): print('NO') sys.setrecursionlimit(10 ** 9) INF = 10 ** 18 MOD = 10 ** 9 + 7 EPS = 10 ** -10 class Geometry: """ 幾何学計算用クラス """ def __init__(self, EPS): self.EPS = EPS def add(self, a, b): x1, y1 = a x2, y2 = b return (x1+x2, y1+y2) def sub(self, a, b): x1, y1 = a x2, y2 = b return (x1-x2, y1-y2) def mul(self, a, b): x1, y1 = a if not isinstance(b, tuple): return (x1*b, y1*b) x2, y2 = b return (x1*x2, y1*y2) def div(self, a, b): x1, y1 = a if not isinstance(b, tuple): return (x1/b, y1/b) x2, y2 = b return (x1/x2, y1/y2) def abs(self, a): from math import hypot x1, y1 = a return hypot(x1, y1) def norm(self, a): x, y = a return x**2 + y**2 def dot(self, a, b): x1, y1 = a x2, y2 = b return x1*x2 + y1*y2 def cross(self, a, b): x1, y1 = a x2, y2 = b return x1*y2 - y1*x2 def project(self, seg, p): """ 線分segに対する点pの射影 """ p1, p2 = seg base = self.sub(p2, p1) r = self.dot(self.sub(p, p1), base) / self.norm(base) return self.add(p1, self.mul(base, r)) def reflect(self, seg, p): """ 線分segを対称軸とした点pの線対称の点 """ return self.add(p, self.mul(self.sub(self.project(seg, p), p), 2)) def ccw(self, p0, p1, p2): """ 線分p0,p1から線分p0,p2への回転方向 """ a = self.sub(p1, p0) b = self.sub(p2, p0) # 反時計回り if self.cross(a, b) > self.EPS: return 1 # 時計回り if self.cross(a, b) < -self.EPS: return -1 # 直線上(p2 => p0 => p1) if self.dot(a, b) < -self.EPS: return 2 # 直線上(p0 => p1 => p2) if self.norm(a) < self.norm(b): return -2 # 直線上(p0 => p2 => p1) return 0 def intersect(self, seg1, seg2): """ 線分seg1と線分seg2の交差判定 """ p1, p2 = seg1 p3, p4 = seg2 return ( self.ccw(p1, p2, p3) * self.ccw(p1, p2, p4) <= 0 and self.ccw(p3, p4, p1) * self.ccw(p3, p4, p2) <= 0 ) def get_distance_PP(self, p1, p2): from math import hypot x1, y1 = p1 x2, y2 = p2 return hypot(x1-x2, y1-y2) def get_distance_LP(self, line, p): """ 直線lineと点pの距離 """ p1, p2 = line return abs(self.cross(self.sub(p2, p1), self.sub(p, p1)) / self.abs(self.sub(p2, p1))) def get_distance_SP(self, seg, p): """ 線分segと点pの距離 """ p1, p2 = seg if self.dot(self.sub(p2, p1), self.sub(p, p1)) < 0: return self.abs(self.sub(p, p1)) if self.dot(self.sub(p1, p2), self.sub(p, p2)) < 0: return self.abs(self.sub(p, p2)) return self.get_distance_LP(seg, p) def get_distance_SS(self, seg1, seg2): """ 線分seg1と線分seg2の距離 """ p1, p2 = seg1 p3, p4 = seg2 if self.intersect(seg1, seg2): return 0 return min( self.get_distance_SP(seg1, p3), self.get_distance_SP(seg1, p4), self.get_distance_SP(seg2, p1), self.get_distance_SP(seg2, p2), ) def get_cross_pointSS(self, seg1, seg2): """ 線分seg1と線分seg2の交点 """ p1, p2 = seg1 p3, p4 = seg2 base = self.sub(p4, p3) dist1 = abs(self.cross(base, self.sub(p1, p3))) dist2 = abs(self.cross(base, self.sub(p2, p3))) t = dist1 / (dist1+dist2) return self.add(p1, self.mul(self.sub(p2, p1), t)) def intersectCL(self, c, line): """ 円cと直線lineの交差判定 """ x, y, r = c return self.get_distance_SP(line, (x, y)) <= r def get_cross_pointCL(self, c, line): """ 円cと直線lineの交点 """ from math import sqrt if not self.intersectCL(c, line): return -1 x, y, r = c p1, p2 = line pr = self.project(line, (x, y)) e = self.div(self.sub(p2, p1), self.abs(self.sub(p2, p1))) base = sqrt(r*r - self.norm(self.sub(pr, (x, y)))) return [self.add(pr, self.mul(e, base)), self.sub(pr, self.mul(e, base))] def arg(self, p): from math import atan2 x, y = p return atan2(y, x) def polar(self, a, r): from math import sin, cos return (cos(r)*a, sin(r)*a) def intersectCC(self, c1, c2): """ 円c1と円c2の交差判定 """ from math import hypot x1, y1, r1 = c1 x2, y2, r2 = c2 return hypot(x1-x2, y1-y2) <= r1 + r2 def get_cross_pointCC(self, c1, c2): """ 円c1と円c2の交点 """ from math import acos if not self.intersectCC(c1, c2): return -1 x1, y1, r1 = c1 x2, y2, r2 = c2 try: d = self.abs(self.sub((x1, y1), (x2, y2))) a = acos((r1*r1+d*d-r2*r2) / (2*r1*d)) t = self.arg(self.sub((x2, y2), (x1, y1))) return [self.add((x1, y1), self.polar(r1, t+a)), self.add((x1, y1), self.polar(r1, t-a))] except: # 一方が他方を内包しちゃってる場合等はここに飛ぶ(はず) return -1 x, y, r = MAP() gm = Geometry(EPS) x = abs(x) y = abs(y) dist1 = gm.get_distance_PP((0, 0), (x, y)) + r d = 1 while 1: line = ((d, 0), (0, d)) dist2 = gm.get_distance_SP(line, (0, 0)) if dist1 < dist2: print(d) break d += 1