#include <math.h>
#include <stdio.h>

char *point[] = {
     "N","NbE","NNE","NEbN","NE","NEbE","ENE","EbN",
     "E","EbS","ESE","SEbE","SE","SEbS","SSE","SbE",
     "S","SbW","SSW","SWbS","SW","SWbW","WSW","WbS",
     "W","WbN","WNW","NWbW","NW","NWbN","NNW","NbW"};

double p[1000],s[1000],x,y,xx,yy,X,Y,d,dist;
int i,j,k,m,n;
char tmp[100];

follow(double d){
   int i; 
   double dd;
   dist = 0;
   x = 0;
   y = 0;
   dist = hypot(X,Y);
   for (i=0;i<n;i++) {
      xx = x + s[i]*cos(p[i]-d);
      yy = y + s[i]*sin(p[i]-d);
      dd = hypot(X-xx,Y-yy);
      if (dd < dist) dist = dd;
      if ((X-x)*(xx-x)+(Y-y)*(yy-y) > 0 && (X-xx)*(x-xx)+(Y-yy)*(y-yy) > 0) {
         dd = fabs(((X-x)*(yy-y) - (Y-y)*(xx-x))/hypot(xx-x,yy-y));
         if (dd < dist) dist = dd;
      }
      x = xx;
      y = yy;
   }
}

main(){
   while (1 == scanf("%d",&n) && n){
      for (i=0;i<n;i++) {
         scanf("%s%lf",tmp,&s[i]);
         for (j=0;j<32 && strcmp(tmp,point[j]);j++);
         p[i] = M_PI*j/16;
      }
      scanf("%lf",&d);
      follow(0);
      X = x; Y = y;
      follow(M_PI*d/180);
      printf("%0.2lf\n",dist);
   }
   if (n) printf("missing delimter\n");
}