#include <iostream>
#include <algorithm>
#include <cmath>
#include <cstdlib>
using namespace std;
int main()
{
/*
1. Napisać program obliczania wartości wyrażenia wg wzoru
F = (3*z + 2*x + 1)/2;
*/
double x, z;
double F;
cin >> x >> z;
F = (3*z + 2*x +1)/2;
cout << "F = " << F << endl;
return 0;
}
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