#include <iostream>
#include <cmath>
#include <iomanip>

using namespace std;

int main()
{
    double vi, vf, c, d, g , f, x, u;

    x=pow(vf,2)+2*c*d*g*f;
    vi=sqrt(x);

    cout<<"type 1 for metric  2 for us units"<<endl;
    cin>>u;
 if (u==1)

   vf=50;
   d=200;
   f=.14;
   c=12.96;
   g=9.81;
   cout<< "speed before skid"<<vi<<"km/hr"<<endl;

        else-if (u==2)
   vf=40;
   d=400;
   f=.145;
   c=.4649;
   g=32.2;
   cout<< "speed before skid"<<vi<<"mi/hr"<<endl;

     else
   cout<<"select again"<<endl;
 )

    return 0;
}