function

#include<iostream>
using namespace std;

string encrypt(string username);

void print()
{
    cout<<"hello\n";
}

string encrypt(string username)
{
    print();
    print();
    string encrypted_username = "FB" + username;
    return encrypted_username;
}

int sum(float a, float b)
{
    return a+b;
}

int f(int a)
{
    a= a+2;
    return a;
}

void avg(int a[], int array_size)
{
    double total = 0;
    for(int i=0; i<array_size; i++) {
        total = total + a[i];
    }
    cout<<"avg marks: "<<(total)/array_size<<endl;
}

int main()
{
    string username = "mou";
    cout<<encrypt(username)<<endl;
    int a = 5;
    a = f(a);
    cout<<a<<endl;

    int arr[3];
    int array_size = 3;
    for(int i=0; i<array_size; i++) {
        arr[i] = i+1;
    }
    avg(arr,3);

    return 0;
}