You work as a financial consultant and help families plan accumulations. One of the popular accumulation strategies is based on the sequence of Fibonacci - every month the family deals an amount equal to the amount of the two previous months. In the first month, 1 ruble is put off, in the second - also 1 ruble, in the third - 2 rubles, in the fourth - 3 rubles and so on. You need to create a program that will determine how many rubles you need to postpone this month.
Input format
one number n (1 & le; n & le; 30)-number of the month
Output format
one number-the amount for deposit in the nth month of
Hint
There will be no clue here, decide for yourself!