PROGRAM KAIJOW
      INTEGER*8 N,KAIJO
      WRITE(*,*)'N='
      READ(*,*)N
      WRITE(*,*)KAIJO(N)
      END
      INTEGER*8 FUNCTION KAIJO(N)
      INTEGER*8 I,N
      KAIJO=1
      DO I=2,N
          KAIJO=KAIJO*I
      END DO
      RETURN
      END