Problems
Cost of call
Cost of call
Find the cost of a phone call in kopecks with duration of n seconds, if the connecting cost is a kop., the tariffication is per minute, that is the first second of each minute is charged to pay b kop.
Input data
Three non-negative integers a, b and n~(0 \le a, b \le 99, 0 \le n \le 86400).
Output data
Print the cost of a phone call in kopecks.
Examples
Input example #1
5 10 120
Output example #1
25