KEK

#include <stdio.h>
#include <math.h>
//#include <time.h>
//#include <limits.h>

void main() {
//    INT_MAX
//    clock_t begin = clock();

    int acc, n = 0, st;
    long double S1=0, r, rr, an;

    scanf("input the accuracy: %d",&acc);
    //acc = 8;
    rr = pow(10,-(acc+1));
    //r=pow(10,-acc);
    st=1;

    do {
        an = (long double)4*st/(2LL*n+1);
        /*printf("%1.14f\n",an);*/
        S1 += an;
        n++;
        st = -st;
//        if (n % 100000 == 0)
//            printf("%d\n", n);
//        if (n >= 2000000000){
//            printf("ALALALLALALAL");
//        }
    } while(fabs(an) >= rr);

    //printf("%f\n",S2);

    printf("%1.14f\n",S1);

    /*if(((S2/r)-(int)(S2/r))>=5*rr) {
        S2o=S2-5*rr;
      } else {
        S2o=S2;
      }*/

    /*printf("%f\n",S2o);*/

    printf("%d\n",n-1);
//    clock_t end = clock();
//    double time_spent = (double)(end - begin) / CLOCKS_PER_SEC;
}