15

#include <iostream>
#include <cmath>
using namespace std;

int main() {
   float x,y;
    cin>>x;
    if (((sin(3*x))==0) || ((12*(x*x)+7*x-5)==0))
      cout<< "Решений нет";   
      else {y=(2*(cos(3*x)/sin(3*x))-(1/(12*(pow(x,2))+7*x-5)));
      cout<<y;}
    return 0;
}