11,21,33,34,45,54,60
First add 11+21=32
Arrange in order
32,33,34,45,54,60
Add first 32+33=65
Arrange in order
34,45,54,60,65
Add first two 34+45=79
Arrange in order
54,60,65,79
Add first two 54+60=114
65,79,114
Add first two 65+79=144
Arrange in order
114,144
Add 114+144= 258..