#include <stdio.h>
 
int xynta(unsigned n) // n > 3
{
    static int yoba[50000001];
 
    yoba[1] = 1;
 
    for (int i = 2; i <= n; ++i)
        yoba[i] = i - yoba[yoba[i - 1]];
 
    return yoba[n];
}
 
int main(void)
{
    printf("%d\n", xynta(50000000));
 
    return 0;
}