/*
#include <stdio.h>
int n;
void f(int x)
{
if(x<=0)return;
f(x-1);
printf("%d ",x);
}
int main()
{
scanf("%d",&n);
f(n);
}
*/
/*
#include <stdio.h>
int x;
void y(int z)
{
if(z<=0)return;
y(z-1);
printf("%d ",z);
}
void f(int z)
{
if(z<=0)return;
f(z-1);
y(z);
printf("\n");
}
int main()
{
scanf("%d",&x);
f(x);
}
f(n) : 1 ~ n 출력
: 1 ~ n-1출력 -> n출력
: f( n-1 ) -> n출력
f(n) : 1 ~ n 합 리턴
: 1 ~ n-1합 + n 리턴
: f(n-1) + n 리턴
*/
/*
#include <stdio.h>
int f(int x)
{
if(x==0)return 0;
return f(x-1)+x;
}
int main()
{
int x;
scanf("%d",&x);
printf("%d",f(x));
}
*/
/*
#include <stdio.h>
int f(int x)
{
if(x==1)return 1;
return f(x-1)*x;
}
int main()
{
int x;
scanf("%d",&x);
printf("%d",f(x));
}
*/
/*
#include <stdio.h>
int f(int x)
{
if(x==1 || x==2)return 1;
return f(x-1)+f(x-2);
}
int main()
{
int x;
scanf("%d",&x);
printf("%d",f(x));
}
*/