your math teacher give follow problemthere n segment xaxis l_1 r_1 l_2 r_2 ldot l_n r_n the segment l r include bound ie set x l le x le r the length segment l r equal r lTwo segment b c d common point intersect exist x leq x leq b c leq x leq d for example 2 5 3 10 common point 5 6 1 4 do not haveyou add segment common point give segment short possible ie minimal length the require segment degenerate point ie segment length zero the add segment give n segmentsIn word need find segment b b l_i r_i common point ba minimal