program avec
       
       real vv(200),hh(200),hv(200),vh(200)
       real vvav,hhav,vhav,hvav
       real vvdb,hhdb,vhdb,hvdb

       integer ntrace,mark,i

       character filename*13

	print *, 'Enter file name'
	read(*,'(a13)') filename 

	open(unit=20,file=filename)

	read(20,*) ntrace

	do  10 i=1,ntrace

	  read(20,*) vv(i),hh(i),vh(i),hv(i)   

	  vv(i)=10.0**(vv(i)/10.)
	  hh(i)=10.0**(hh(i)/10.)
	  vh(i)=10.0**(vh(i)/10.)
	  hv(i)=10.0**(hv(i)/10.)


  10	continue	

	close(20) 


        mark=ntrace
                  

c       cccccccccccccccccccccc
c	open file #2
c       cccccccccccccccccccccc 

	print *, 'Enter file name'
	read *, filename 

	if(filename .eq. 'stop') then
	goto 40
	else
	continue
	endif


	open(unit=20,file=filename)

	read(20,*) ntrace

	do  20 i=mark+1,mark+ntrace,1

	  read(20,*) vv(i),hh(i),vh(i),hv(i)  

	  vv(i)=10.0**(vv(i)/10.)
	  hh(i)=10.0**(hh(i)/10.)
	  vh(i)=10.0**(vh(i)/10.)
	  hv(i)=10.0**(hv(i)/10.)

  20	continue	

	close(20) 

	mark=ntrace+mark  
                       

c       cccccccccccccccccccccc
c	open file #3
c       cccccccccccccccccccccc 
               
	print *, 'Enter file name'
	read *, filename  

	if(filename .eq. 'stop') then
	goto 40
	else
	continue
	endif

	open(unit=20,file=filename)

	read(20,*) ntrace

	do  30 i=mark+1,mark+ntrace,1

	  read(20,*) vv(i),hh(i),vh(i),hv(i)  

	  vv(i)=10.0**(vv(i)/10.)
	  hh(i)=10.0**(hh(i)/10.)
	  vh(i)=10.0**(vh(i)/10.)
	  hv(i)=10.0**(hv(i)/10.)

  30	continue	

        mark=mark+ntrace

	close(20) 

 40     continue

        vvav=0.0
        hhav=0.0
        vhav=0.0
        hvav=0.0

        do 50 i=1,mark

           vvav=vvav+vv(i)/mark
           hhav=hhav+hh(i)/mark
           vhav=vhav+vh(i)/mark
           hvav=hvav+hv(i)/mark
     
 50     continue
 
        vvdb=10.*alog10(vvav)
        hhdb=10.*alog10(hhav)
        vhdb=10.*alog10(vhav)
        hvdb=10.*alog10(hvav)

c        print*, vvdb,hhdb,vhdb,hvdb,mark
        
        open(unit=20,file='avec.out',access='append')
        write(20,*)  vvdb,hhdb,vhdb,hvdb,mark
        close(20)

        stop

        end