BlueBook

The population of a certain country has been increasing at an average rate of $P$ percent each year. Assuming that the population was $A$ in year $Y$, write a program that finds the year in which the population will reach $B$ if the growth pattern continues.

Input, Output

The order of input will be $P$, $A$, $Y$, $B$. Output should be in whole numbers (i.e. no decimals).

Sample Input

5.5 24000000 1980 100000000

Sample Output

2007