#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; //conversion //------------------------------------------ inline int toInt(string s) {int v; istringstream sin(s);sin>>v;return v;} template inline string toString(T x) {ostringstream sout;sout< inline T sqr(T x) {return x*x;} //typedef //------------------------------------------ typedef vector VI; typedef vector VVI; typedef vector VS; typedef pair PII; typedef long long LL; //container util //------------------------------------------ #define ALL(a) (a).begin(),(a).end() #define RALL(a) (a).rbegin(), (a).rend() #define PB push_back #define MP make_pair #define SZ(a) int((a).size()) #define EACH(i,c) for(typeof((c).begin()) i=(c).begin(); i!=(c).end(); ++i) #define EXIST(s,e) ((s).find(e)!=(s).end()) #define SORT(c) sort((c).begin(),(c).end()) //repetition //------------------------------------------ #define FOR(i,a,b) for(int i=(a);i<(b);++i) #define REP(i,n) FOR(i,0,n) //constant //-------------------------------------------- const double EPS = 1e-10; const double PI = acos(-1.0); //clear memory #define CLR(a) memset((a), 0 ,sizeof(a)) //debug #define dump(x) cerr << #x << '=' << (x) << endl; #define debug(x) cerr << #x << '=' << (x) << '('<<'L' << __LINE__ << ')' << ' ' << __FILE__ << endl; const int MAX_N=1234567; int prime[MAX_N];bool is_prime[MAX_N+1]; int pownum[MAX_N]; int num=0; //エラトステネスのふるい int sieve(int n){ REP(i,MAX_N){is_prime[i]=true;} is_prime[0]=is_prime[1]=false; for(int i=2;i<=n;i++){ if(is_prime[i]){ prime[num++]=i; for(int j=2*i;j<=n;j+=i){ is_prime[j]=false; //pownum[j]++; } } } } //ざる int primez[MAX_N];bool is_primez[MAX_N+1]; int num2=0; int zaru(int n){ REP(i,MAX_N){is_primez[i]=true;} is_primez[0]=is_primez[1]=false; for(int i=2;i<=n;i++){ if(is_primez[i]){ primez[num++]=i; for(int j=2*i;j<=n;j+=i){ //is_prime[j]=false; pownum[j]++; } } } } int main(){ int N; double p; cin>>N>>p; sieve(N); zaru(N); double ans=0.0; for(int i=2;i<=N;i++){ if(is_prime[i]){ //cerr<