C Adding up histograms from mulitple hbook files.
C Dmitri Madigojine for NA48
C 
C Compile:  "f77 mhbook.f -o mhbook -L `cernlib mathlib graflib`"
C Use: "ls /path/*.hbook | ./mhbook"

	program sum
	
	character*80 filn
        logical FIRST
        
	integer NWPAWC
	parameter (NWPAWC=8000000)
	common/PAWC/PAW(NWPAWC)
	
	call HLIMIT(NWPAWC)

        FIRST=.TRUE.

 1	read(*,1000,END=3000)filn
1000    format(A80)

        print 1000,filn

        if(FIRST)then
            call hrget(0,filn," ")
            FIRST=.FALSE.
        else
            call hrget(0,filn,"A")
        endif
        			   
	goto 1
	
3000    call hrput(0,"compact.hbook","N")
	
	stop
	end