simple span
xxxxxxxxxxxxx
+
broken span
xxxx xxxxxxxx
        
+
two broken spans
xxxx xxx

  xxxxxxxxxxxxx x
+
big jump span
xxxx



    xxxx
+
climbing back
xx    

      xx
  xxxx
+
enterprise

x xx
 x      xxxx
       x
    xxx

+
no way back up
xxxx  xx


    xx
+
long climb up
x     xxxxxx
     x
    x
   x
  x
 x