1 #include <iostream>
 2 #include <stdio.h>
 3 #include <algorithm>
 4 #include <string.h>
 5 #include <cmath>
 6 using namespace std;
 7 double D;
 8 double sum;
 9 struct node
10 {
11     double l,r;
12 };
13 node ans[3][2];
14 node solve(double a,double b)
15 {
16     node qu;
17     if(a>0)
18     {
19         qu.l=(D-b)/a;
20         qu.r=(360-D-b)/a;
21     }
22     else
23     {
24         qu.l=(360-D-b)/a;
25         qu.r=(D-b)/a;
26     }
27     if(qu.l<0) qu.l=0;
28     if(qu.r>60) qu.r=60;
29     if(qu.l>=qu.r) { qu.l=qu.r=0;}
30     return qu;
31 }
32 node mer_g(node a,node b)
33 {
34     node q;
35     q.l=max(a.l,b.l);
36     q.r=min(a.r,b.r);
37     if(q.l>q.r) q.l=q.r=0;
38     return q;
39 }
40 int main()
41 {
42     int h,m;
43     int i,j,k;
44     double a1,a2,a3,b1,b2,b3;
45     while(scanf("%lf",&D),D!=-1)
46     {
47         sum=0;
48         node qu;
49        for(h=0;h<12;h++)
50          for(m=0;m<60;m++)
51             {
52                b1=m*6;        a1=-5.9;
53                b2=30*h+(0.5-6)*m; a2=1.0/120-0.1;
54                b3=30*h+0.5*m; a3=1.0/120-6;
55                ans[0][0]=solve(a1,b1);ans[0][1]=solve(-a1,-b1);
56                ans[1][0]=solve(a2,b2);ans[1][1]=solve(-a2,-b2);
57                ans[2][0]=solve(a3,b3);ans[2][1]=solve(-a3,-b3);
58               for(i=0;i<2;i++)
59                for(j=0;j<2;j++)
60                 for(k=0;k<2;k++)
61                  {
62                    qu=mer_g(mer_g(ans[0][i],ans[1][j]),ans[2][k]);
63                    sum+=qu.r-qu.l;
64                  }
65             }
66       printf("%.3lf\n",sum*100/43200);
67     }
68     return 0;
69 }