#include using namespace std; using ll=long long; using pll=pair; using tll=tuple; using ld=long double; const ll INF=(1ll<<60); #define rep(i,n) for (ll i=0;i<(ll)(n);i++) #define all(v) v.begin(),v.end() template void chmin(T &a,T b){ if(a>b){ a=b; } } template void chmax(T &a,T b){ if(a> r >> k; ld sum=0; ld x=r*r*(ld)M_PI/(ld)(k+1); vector ans; rep(i,(ll)k/2){ ld ok=r,ng=-r; while(0.0000001