# include <stdio.h>

int inmultire( int a, int b, int N )
{
    int x,c,r;

    if( a >= N )
        a %= N;
    if( b >= N )
        b %= N;

    x = a;
    c = x*b/N;
    r = (a * b - c * N) % N;
    return r < 0 ? r + N : r;
}

int main()
{
    int N,rez,i;

    scanf("%d",&N);
    rez = 1;
    for( i = 2 ; i < N ; ++i )
        rez = inmultire(rez,i,N);

    printf("%d",rez);

    return 0;
}