you give string s1 s2 equal length consist letter x y your task string equal you swap character belong different string means swap s1i s2jreturn minimum number swap require s1 s2 equal return 1 impossible Example 1input s1 xx s2 yyoutput 1explanation swap s10 s21 s1 yx s2 yxexample 2input s1 xy s2 yxoutput 2explanation swap s10 s20 s1 yy s2 xxSwap s10 s21 s1 xy s2 xyNote swap s10 s11 s1 equal yx cause swap char different stringsExample 3input s1 xx s2 xyOutput 1 Constraints1 s1length s2length 1000s1 s2 contain x y