PROGRAMMING:Calculate deposit interest
This topic requires the calculation of deposit interest, the calculation formula is $$interest = money times (1 + rate) ^ {year} - money $$, where $$interest $$is the interest at the time of deposit maturity (before tax), $$money $$is the deposit amount, $$year $$is the deposit period, and $$rate $$is the annual interest rate.
###Input format:
The input gives three positive real numbers $$money $$, $$year $$, and $$rate $$, separated by spaces, in a row.
###Output format:
Output in the format of "interest = interest" in one line, where the interest retains two decimal places.
###Input example:
```in
1000 3 0.025
```
###Output example:
```out
interest = 76.89
```
answer：If there is no answer, please comment
###Input format:
The input gives three positive real numbers $$money $$, $$year $$, and $$rate $$, separated by spaces, in a row.
###Output format:
Output in the format of "interest = interest" in one line, where the interest retains two decimal places.
###Input example:
```in
1000 3 0.025
```
###Output example:
```out
interest = 76.89
```
answer：If there is no answer, please comment