The target heart rate can be obtained by adding the resting heart rate to the product of the target intensity (a number between 0 and 1) and the heart rate reserve.

The heart rate reserve is the difference between the maximum heart rate and the resting heart rate.

The maximum heart rate is calculated as 220 minus the age.

For the values given, print the target heart rate.

Input

The inputs are age, resting heart rate and intensity.

Output

The target heart rate.

Sample Input

20
65
0.7

Sample Output

159.5