int(int) fibonacci = (index) {
int a = 1
int b = 1
if index == 1 {
return 1
} else {
(2..index).for_each((_) {
int c = a + b
a = b
b = c
})
}
b
}
int target_fib = @int(@input("What fib number? "))
int result = fibonacci(target_fib)
@print("{target_fib}th fibonacci is {result}")