program matrixmult
      character*20 arg
      if (IARGC() .ne. 1) then
         print *,"Need one argument."
         return
      end if
      call GETARG(1,arg)
      call mult(intchr(arg))
      end

      subroutine mult(n)
      integer n, i, j, k
      double precision M(n,n)
      do 1 i=1,n
         do 2 j=1,n
            M(i,j)=i+j+0.5
 2       continue
 1    continue
      r=0
      do 3 i=1,n
         do 4 j=1,n
            do 5 k=1,n
               r=r+M(i,k)*M(k,j)
 5          continue
 4       continue
 3    continue
      print *,r
      return
      end

      integer function intchr(cc)
      character cc*(*)
      integer i, l, ii, j
      l = len(cc)
      ii = 1
      intchr = 0
      do 6 j = l, 1, -1
         if (cc(j:j) .ne. ' ') then
            intchr = intchr + max0(0,ichar(cc(j:j))-48) * ii
            ii = ii * 10
         end if
 6    continue
      return
      end