fortran90，求帮看看代码哪错了

公鸡5钱一只，母鸡3钱一只，鸡仔三只1钱，100钱买100只鸡， 问公鸡、母鸡，鸡仔的个数？

PROGRAM Main
integer:x,y,z,n=0,sum
real::m
ii: do x=0,100
jj: do y=0,100
ZZ: do z=0,100
sum=x+y+z
if(sum/=100)then exit
m=5x+3y+z/3
if(sum==100.or.abs(m-100)<1e-6) then
n=n+1
write(*,100) n,x,y,Z
end if
end do ii
end do jj
end do zz
100 format(1x,"第",l2,'组解:','公鸡',l2,'只'，'母鸡',l2'只'，'鸡仔',l2,'只')
END PROGRAM Main

  program main
  ! x+y+z=100
  !5x+3y+z/3=100
  !15x+9y+z=300
  !3-1: 7x+4y=100
  !y <= 25
  !x <=14
  implicit none
  integer::x,y,z,n=0,sum, m
  ii: do x=0,14 ! 100
    jj: do y=0,25 ! 100
      if(x+y>100) exit
      zz: do z=0,100,3 !z为3的倍数
        sum=x+y+z
        if(sum>100) then
          exit
        else if(sum==100)then
          m=15*x+9*y+z
          if(m==300) then
            n=n+1
            write(*,100) n,x,y,z
          end if
        end if
      end do zz
    end do jj
  end do ii
100 format(1x,"第",i0,'组解: ','公鸡',i2,'只,','母鸡',i2'只,','鸡仔',i2,'只.')
  pause
  end program main

更简单的

  program main
  !x+y+z=100
  !5x+3y+z/3=100
  !15x+9y+z=300
  !3-1: 7x+4y=100
  !y <= 25
  !x <=14
  implicit none
  integer::x,y,z,n=0,sum, m
  do x=0,14 ! 100
    !7x+4y=100
    m = 100-7*x
    if(mod(m,4)==0) then
      y = m / 4
      z = 100-x-y
      n=n+1
      write(*,100) n,x,y,z
    end if
  end do
100 format(1x,"第",i0,'组解: ','公鸡',i2,'只,','母鸡',i2'只,','鸡仔',i2,'只.')
  pause
  end program main