#include
#include
using namespace std;
#define ll long long
#define ld long double
ld average(ld a, ld b, ld c){
return (a+b+c)/3;
}
signed main(){
cout << average(1, 2, 3) << "\n";</strong>
cout << average(100, 50, 3) << "\n";</strong>
cout << average(9865, 678, 665);</strong>
}