Initialize first row - First width of tSum array
for ( i = 1 ; i < l ; i ++ ) for ( k = 1 ; k < n ; k ++ ) tSum [ i , 0 , k ] = min ( tSum [ i - 1 , 0 , k ] , tSum [ i , 0 , k - 1 ] , int . MaxValue ) + arr [ i , 0 , k ] ;