#include <stdio.h>
#include <iostream>
using namespace std;
int main()
{
	int n;
	0 <= n <= 25;
	cin >> n;
	if (n>=0 && n<=3)
	{
		cout<<"infant";
	}
    else if (n>=4 && n<=12)
    {
    	cout<<"child";

    }
    else if (n>=13 && n<=18)
    {
    	cout<<"youngster";
    }
    else if (n>=19 && n<=25)
    {
    	cout<<"youth";
    }

}

```#include
#include <iostream>
using namespace std;
int main()
{
int n;
for( ; ; ){
cout<<"你不讲武德，你是猪🐖";
0 <= n <= 25;
cin >> n;
if (n>=0 && n<=3)
{
cout<<"infant";
}
else if (n>=4 && n<=12)
{
cout<<"child";}
}

int a,b,c,d;

cin>>a;

if(a>=0&&a<=3){

	cout<<"infant";

}else{

	if(a>=4&&a<=12){

		cout<<"child";

	}else{

		if(a>=13&&a<=18){

			cout<<"youngster";

		}else{

			if(a>=19&&a<=25){

				cout<<"youth";

			}

		}

	}

}

#include <stdio.h>
#include <iostream>
using namespace std;
int main()
{
	int n;
	0 <= n <= 25;
	cin >> n;
	if (n>=0 && n<=3)
	{
		cout<<"infant";
	}
    else if (n>=4 && n<=12)
    {
    	cout<<"child";

    }
    else if (n>=13 && n<=18)
    {
    	cout<<"youngster";
    }
    else if (n>=19 && n<=25)
    {
    	cout<<"youth";
    }

}

#include <stdio.h>
#include <iostream>
using namespace std;
int main()
{
	int n;
	0 <= n <= 25;
	cin >> n;
	if (n>=0 && n<=3)
	{
		cout<<"infant";
	}
    else if (n>=4 && n<=12)
    {
    	cout<<"child";

    }
    else if (n>=13 && n<=18)
    {
    	cout<<"youngster";
    }
    else if (n>=19 && n<=25)
    {
    	cout<<"youth";
    }

}

#include <stdio.h>
#include <iostream>
using namespace std;
int main()
{
	int n;
	cin >>n;
	if(n >=0 && 3 >= n)
	{
		cout <<"infant";
	}
	else if(n >=4 && 12 >= n)
	{
		cout <<"child";
	}
	else if(n >=13 && 18 >= n)
	{
		cout <<"youngster";
	}
	else if(n >=19 && 25 >= n)
	{
		cout <<"youth";
	}
}

#include <iostream>
#include <math.h>
#include <iomanip>
using namespace std;
int main()
{
	int n;
	0<=n<=25;
	cin >>n;
	if(0<=n&&n<=3)
	{
		cout<<"infant";
	}
	else if(4<=n&&n<=12)
	{
		cout<<"child";
	}
	else if(13<=n&&n<=18)
	{
		cout<<"youngster";
	}
	else
	{
		cout<<"youth";
	}
}