import java.math.BigInteger;
public class Power{
static int power(int a, int b){
int return_val;
Trace.reverseIndent(b,"a= "+a + " b="+b);
if (b==0) {
return_val = 1;
} else if ( b % 2 == 0) {
return_val = power(a*a, b/2);
} else {
return_val = a*power(a,b-1);
}
Trace.reverseIndent(b,"power(a,b)= "+return_val);
return return_val;
}
public static void main(String args[]){
System.out.println(power(7,9));
}
}