Program to test whether a year is leap year or not

C      Program to test whether a year is leap year or not
        write(*,*)'Enter the year:'
        read(*,*)l
        if (mod(l,4).ne.0)goto 10
        if (mod(l,100).ne.0)goto 20
        if (mod(l,400).ne.0)goto 10
20    write(*,*)'The year is a leap year.'
        stop
10    write(*,*)'The year is  not a leap year.'
        stop
        end