#include int main( ){ int k; int s[6] = { 2, 3, 5, 7, 11, 13 }; int g[6] = { 4, 6, 8, 9, 10, 12 }; int count = 0; double ans = 0; scanf("%d", &k); for(int i = 0; i < 6; i++) { for(int j = 0; j < 6; j++) { if(s[i] * g[j] == k) { count++; } } } ans = (double)count / 36.0; printf("%lf\n", ans); return 0; }