Mahmud was seized near Tikrit , the area from which he and Saddam hail , about 150 kilometres north-west of Baghdad , US military officials said .
Mahmud was seized near Tikrit , the area from which he and Hussein hail , about 90 miles north of Baghdad , U.S. military officials said Wednesday night .
assuming n features examine all (n d) subsets of size d select subset that performs best according to criterion function