4 14 1
let x0 = 0
let x1 = 1
let x2 = 42
if x0 >= x2 goto 7
while x0 < x2 exit 9
while x0 >= x2 exit +1
if x0 >= x2 goto 12
let x0 = x0 + x1
next
let x2 = x0 + x1
rem output should be 43
end
let x2 = 420
end
