C++ nested of member functions

#include<iostream>
using namespace std;
class Set
{
int m,n;
public :
void input();
void display();
int largest();
};
int Set:: largest()
{
if (m>=n)
return (m);
else
return (n);
}

void Set::input()
{
std::cout <<"input values of m and n"<<"\n";
std::cin>>m>>n;
}
void Set:: display()
{
std::cout <<"largest value=" <<largest() << "\n"; // calling the member function
}
int main()
{
Set s;
s.input();
s.display();
}

output: input values of m and n
45 67
largest value=67