PROGRAM F2A
      I=35; K=I
      CALL F(I)
      PRINT *,K,'th Fibonacci number is',I
      STOP
      END PROGRAM
C
C Routine F(I) qui calcule le  I ième nombre de Fibonacci
C
      SUBROUTINE F(I)
      DIMENSION A(I+1)
      A(1)=1; A(2)=1
      DO1J=3,I+1
      A(J)=A(J-1)+A(J-2)
1     CONTINUE
      I=A(I+1)
      RETURN
      END SUBROUTINE