long k;c,n,d[1<<18],u[1<<18];main(i){for(scanf("%d%ld",&n,&k);~scanf("%d",d+i++););for(i--;--i;c--)for(;!u[i];i=d[i])u[i]=++c;n=!puts(k<c||k-c&1?"NO":"YES");}