void fib(int i,int *p)
{
    int res1=0, res2=0;

    if (i > 2) {
	fib(i-1,&res1);
	fib(i-2,&res2);
	*p = res1 + res2;
    } else {
	*p = 1;
    }
}
    

main()
{
    int res = 0;

    puts(10,10,"The 20th Fibonacci number is:");
    fib(20,&res);
    putd(10,25,res);
}