#include <stdio.h>
 
int main () {
	int I, F;
	do {
	} while (I >= F);
	for (; I 
< F
; I
++, F
--) printf("%d %d ", I
, F
); 	printf("\nfim de programa\n"); }
 
//https://pt.stackoverflow.com/q/204611/101
				I2luY2x1ZGUgPHN0ZGlvLmg+CgppbnQgbWFpbiAoKSB7CglpbnQgSSwgRjsKCWRvIHsKCQlzY2FuZigiJWQiLCAmSSk7CgkJc2NhbmYoIiVkIiwgJkYpOwoJfSB3aGlsZSAoSSA+PSBGKTsKCWZvciAoOyBJIDwgRjsgSSsrLCBGLS0pIHByaW50ZigiJWQgJWQgIiwgSSwgRik7CglpZiAoSSA9PSBGKSBwcmludGYoIiVkICIsIEkpOwoJcHJpbnRmKCJcbmZpbSBkZSBwcm9ncmFtYVxuIik7Cn0KCi8vaHR0cHM6Ly9wdC5zdGFja292ZXJmbG93LmNvbS9xLzIwNDYxMS8xMDE=