#include <iostream>
#include <iomanip> 
using namespace std;
int main() {
double a,b,c,d;
cin>>a>>b>>c>>d;
cout<<fixed<<setprecision(2)<<(a+b+c+d)/4.0<<endl;
return 0;
}

$#doanthevu$

Code C++ :

#include <bits/stdc++.h>  
#define ll long long 
using namespace std;  
int main() {  
    double n1, n2, n3, n4;  
    cin >> n1 >> n2 >> n3 >> n4;  
    double gg = (n1 + n2 + n3 + n4) / 4.0;  
    cout << fixed << setprecision(2);  
    cout << gg << endl;  
    return 0;  
}