#include using namespace std; #define FOR(i,a,b) for(int i=(a);i<(b);i++) #define REP(i,n) FOR(i,0,n) #define ALL(v) (v).begin(),(v).end() template inline bool chmax(A &a, B b) { if (a inline bool chmin(A &a, B b) { if (a>b) { a=b; return 1; } return 0; } typedef unsigned long long ull; typedef long long ll; typedef pair pii; typedef pair pll; const ll INF = 1ll<<29; const ll MOD = 1000000007; const double EPS = 1e-10; string to_str(ll x) { stringstream ss; ss << x; return ss.str(); } int main() { ll d; cin >> d; ll p = d * 8; string f = to_str(p); f = "000" + f; f = f.substr(f.size() - 2, 2); printf("%lld.%s\n", d + p / 100, f.c_str()); return 0; }