//tell the first day of those three, when the average temp. was the highest

#include <iostream>
#include <cmath>

using namespace std;

void read(float v[], int);

struct maximum
{
    float max_val;
    int index;
};

maximum maxker_b(float v[], int);

int main()
{

    int db;
    maximum m;
    const int m_val=30;
    do
    {
        cout<<" How many data:  ";
        cin>>db;

         if(db<3)
        cout<<" Not enough! "<<endl;
    }while(db<3);

    float data[m_val];
    read(data, db);

    m = maxker_b(data, db);
    cout<<" the average: "<<m.max_val<<endl;
    cout<<"  the first day: "<<m.index+1<<". th. "<<endl;

    return 0;
}

void read(float h[], int db)
{
    for(int i=0; i<db; ++i)
    {
        cout<<i+1<<". data: ";
        cin>>h[i];
    }
}

maximum maxker_b(float hom[], int db)
{
    maximum m;
    //if(db<2) return m;
    float s=hom[0]+hom[1]+hom[2];
    m.max_val=s/3;
    m.index=0;
    for(int i=0; i<db-3; ++i)
    {
        s-=hom[i];
        s+=hom[i+3];
        if(m.max_val<s/3)
        {
            m.max_val=s/3;
            m.index=i+1;
        }
    }
    return m;
}