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

    
int main(int argc, char** argv)
{
    double z, x;
    
        cout << "x=";
        cin >> x;
        
        if(x >= 1) z = log10(x);
        else if(x > -1 && x < 1) z = 1;
        else if(x <= -1) z = exp(x);
        
        cout << "z=" << z << endl;
    
    return (0);
}