#include "bits/stdc++.h" using namespace std; #define all(x) begin(x),end(x) template<typename A, typename B> ostream& operator<<(ostream &os, const pair<A, B> &p) { return os << '(' << p.first << ", " << p.second << ')'; } template<typename T_container, typename T = typename enable_if<!is_same<T_container, string>::value, typename T_container::value_type>::type> ostream& operator<<(ostream &os, const T_container &v) { string sep; for (const T &x : v) os << sep << x, sep = " "; return os; } #define debug(a) cerr << "(" << #a << ": " << a << ")\n"; typedef long long ll; typedef vector<int> vi; typedef vector<vi> vvi; typedef pair<int,int> pi; const int mxN = 1e5+1, oo = 1e9; int main() { ios_base::sync_with_stdio(false); cin.tie(NULL); double r,k; cin >> r >> k; double vol = r*r*acos(-1); for(int i=1;i<k+1;++i) { double need = vol*i/(k+1); double lo = -r, hi = r; for(int rep=0;rep<50;++rep) { auto mid = (lo+hi)/2; // need to auto calc = [&]() { if(mid<0) { auto ang = acos(abs(mid)/r)*2; double have = ang*r*r/2-(abs(mid)*sqrt(r*r-mid*mid)); return have; } else { auto ang = acos(abs(mid)/r)*2; double have = ang*r*r/2-(abs(mid)*sqrt(r*r-mid*mid)); return vol-have; } }; auto have = calc(); if(have>=need) hi = mid; else lo = mid; } cout << lo << '\n'; } }