#include <stdio.h>
int main()
{
int n,i,sum=0;
scanf_s("%d", &n);
int a[];
for (i=1; i < n; i++)
{
a[i - 1] = 2 * i - 1;
sum += a[i - 1];
}
printf("%d", sum);
return 0;
}
#include <stdio.h>
int main()
{
int n,i,sum=0;
scanf_s("%d", &n);
int a[];
for (i=1; i < n; i++)
{
a[i - 1] = 2 * i - 1;
sum += a[i - 1];
}
printf("%d", sum);
return 0;
}