Points O and N are midpoints of the sides of triangle DEF.

Triangle D E F is cut by line segment O N. Point O is the midpoint of side E D and point N is the midpoint of side E F. The lengths of E O and O D are 22 centimeters. The lengths of E N and N F are 30 centimeters. The length of O N is 38 centimeters. Line segments D M and M F are congruent.

What is DM?