Cost of call#2391

Cost of call

1 second

128 megabytes

Easy

Find the cost of a phone call in kopecks with a duration of $n$ seconds, if the connection cost is $a$ kopecks and the tariff is per minute; that is, at the first second of each minute, a charge of $b$ kopecks is applied.

Input

Three non-negative integers $a$ , $b$ , and $n$ $(0 \leq a, b \leq 99, 0 \leq n \leq 86400)$ (0 \le a, b \le 99,\ 0 \le n \le 86400).

Output

Print the cost of the phone call in kopecks.

Examples

Example 1

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(0 \leq a, b \leq 99, 0 \leq n \leq 86400)