Write a program which takes two integers *x* and *y* and returns the power of *x* to the *y*.

This is very easy in Python using the built-in `pow`

function:

```
def power_x_y(x, y):
return pow(x, y)
```

However, let’s assume we can’t use this built-in function. There’s the very obvious brute force solution where we multiply *x* by itself *y* times:

```
def power_x_y_brute_force(x, y):
if not x and not y:
return 1
total = 1
for _ in range(y):
total *= x
return total
```

This solution runs in *O(y)* time.