#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
// Yukicoder №144 エラトステネスのざる ★★
// https://yukicoder.me/problems/no/144
// ***********************
// for debug
#define DEBUGs
// -----------

#define NOP do{}while(0)
#ifdef DEBUG
#include <time.h>
#define TRACE(...) do{printf(__VA_ARGS__);fflush(stdout);}while(0)
#define TRACECR do{putchar_unlocked('\n');fflush(stdout);}while(0)
static clock_t	startclock;
void DEBUGINIT(void){TRACE("--DEBUG MODE --\n");startclock=clock();}
void DEBUGEND(void){startclock=clock()-startclock;TRACE("--finish --\ntime is %.3fms",startclock/1000.);}
#else
#define TRACE(...) NOP
#define TRACECR NOP
void DEBUGINIT(void){return;}
void DEBUGEND(void){return;}
#endif

#define	mypc(d)	putchar_unlocked((int)(d))
#define PRINCR mypc('\n')
#define NOCR(strig) do{char *p;p=strchr(strig,'\n');if(p)*p='\0';}while(0)
// The out-of-date function
#define	asctime(...)	asctime_s(...)
#define	ctime(...)		ctime_s(...)
#define	strlen(a)	mystr_len(a)

// for stdio
#define GETLINE(str) do{char *p;fgets(str,sizeof(str),stdin);p=strchr(str,'\n');if(p)*p='\0';}while(0)
#define mygc(c) (c)=getchar_unlocked()
static char *GETWORD(char* str) {char c;char *cp;cp=&str[0];mygc(c);while(c!=EOF){if((c==' ')||(c=='\n'))break;*cp++=c;mygc(c);}*cp='\0';return &str[0];}
#define	GETINTS(a,b) {char s[34];int *ap=a;REP(i,b){GETWORD(s);*ap++=atoi(s);}}
static int GETLINEINT(void) {char s[34];GETLINE(s);return atoi(s);}
static int GETWORDINT(void) {char s[34];GETWORD(s);return atoi(s);}
static long GETWORDLONG(void) {char s[34];GETWORD(s);return atol(s);}
static double GETWORDDOUBLE(void) {char s[34];GETWORD(s);return atof(s);}
static int maxi(int a,int b){if((a)>(b)){return a;}return b;}
static long maxl(long a,long b){if(a>b){return a;}return b;}
#define SWAP(type,a,b) do{type _c;_c=a;a=b;b=_c;}while(0)
#define MAX(a,b)	((a)>(b)?(a):(b))
#define MIN(a,b)	((a)<(b)?(a):(b))
#define REP(a,b) for(int a=0;a<(int)(b);++a)
#define REP1(a,b) for(int a=1;a<=(int)(b);++a)
#define Possible(a) 	   printf("%s",((a)?"Possible":"Impossible"))
#define possible(a) 	   printf("%s",((a)?"possible":"impossible"))

// *********************
// *********************
int	SN[1000003];
double	PN[1000003];

// *********************
int main( void ) {
	int	N,m;
	int ep;
	double	P,cnt=0.0;
	DEBUGINIT();
	N = GETWORDINT();
	PN[1] = P = 1.0 - GETWORDDOUBLE();
	REP(i,4) SN[i] = 0;
	for(int i=4; i <= N; i++ ) {
		SN[i] = 0;
	}
	for(int i=2; i <= N; i++ ) {
		PN[i] = PN[i-1] * P;
		ep = N / i;
		m = i;
		for(int k=2; k <= ep ; k++ ){
			m += i;
			if( m <= N ) SN[m]++;
			else break;
		}
	}
	for(int i=2; i <= N; i++ ) {
		//TRACE("SN[%d]is%d,P=%.6f\n",i,SN[i],PN[ SN[i] ]);
		if( SN[i] ) {
			cnt += PN[ SN[i] ];
		} else {
			cnt += 1.0;
		}
	}
	printf("%.6f\n", cnt );
	DEBUGEND();
}