#include //#include //#include using namespace std; //using namespace atcoder; //g++ hoge.cpp (-std=c++17) -I . で実行 #pragma GCC target("avx") #pragma GCC optimize("O3") #pragma GCC optimize("unroll-loops") typedef long long ll; typedef pair prl; typedef vector vcl; typedef map mapl; typedef unordered_map umap; #define pb push_back #define all(v) v.begin(), v.end() #define rep(i,a,b) for(ll i=a;i<=b;i++) #define repi(i,a,b) for(int i=a;i<=b;i++) #define repr(i,a,b) for(ll i=a;i>=b;i--) #define reps(i,v) for(ll i=0;i void chmin(T &a, const T &b) { a = min(a, b); } template void chmax(T &a, const T &b) { a = max(a, b); } ll myceil(ll a, ll b) { if(b < 0){ a = -a; b = -b; } return ((a > 0) ? ((a+b-1) / b) : (-(-a / b)) ); } ll myfloor(ll a, ll b) { if(b < 0){ a = -a; b = -b; } return ((a > 0) ? (a / b) : (-((-a+b-1) / b)) ); } //const ll mod = 1e9+7; //const ll mod = 998244353; //typedef modint1000000007 mint; //typedef modint998244353 mint; //typedef modint mint //cout << sum.val() << endl; //mint::set_mod(mod); modが固定でないとき int main() { // your code goes here double x; cin >> x; fprint(x*4.0*882.0); return 0; }