#include <iostream>
#include <cmath>
using namespace std;
double zaokraglij(double a) {
return round(a*100)/100;
}
int main() {
double a,b,c;
cin>>a>>b>>c;
if (a==0 && c-b!=0)
{
cout<<"NR";
}
else if (a==0 && c-b==0)
{
cout<<"NWR";
}
else{
cout.precision(2);
cout<<fixed<<zaokraglij((c-b)/a);
}
return 0;
}
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