number of columns
let m = 4 ; let M = [ [ 1 , 2 , 3 , 4 ] , [ 9 , 5 , 3 , 1 ] , [ 0 , 3 , 5 , 6 ] , [ 0 , 4 , 5 , 6 ] ] ; if ( areSumSame ( M , n , m ) == true ) document . write ( " " ) ; else document . write ( " " ) ;