if s1<=s2 and s1<=s3 then begin smin1:=s1; if s2<=s3 then begin smin2:=s2; smin3:=s3; end else begin smin2:=s3; smin3:=s2; end end if s2<=s1 and s2<=s3 then begin smin1:=s2; if s1<=s3 then begin smin2:=s1; smin3:=s3; end else begin smin2:=s3; smin3:=s1; end end if s3<=s1 and s3<=s2 then begin smin1:=s3; if s1<=s2 then begin smin2:=s1; smin3:=s2; end else begin smin2:=s2; smin3:=s1; end end for i:=1 to length(smin1) do begin for j:=1 to length(smin2) if smin1[i]=smin2[j] end