動くかどうか調べてない＆初項と次項はループ外

int main(void)
{
int num;
int pf, f1, f2;
int in = 0;

while(!in)
{
num = 0;
printf("最大数入力\n");
scanf("%d", &num);
if (num > 0) in = 1;
}

pf = f1 = 0;
printf("%d\n", f1);
f2 = 1;
printf("%d\n", f2);

while(pf < num)
{
pf = f1 + f2;
f1 = f2;
f2 = pf;
printf("%d\n", pf);
}

return 0;
}