H. Substrings
time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output

Walk Alone has a string, and he wants you to count the number of consecutive 'fyt' in the string.

For example, the answer to 'ffyt' is $$$1$$$ since the second to the fourth character forms a consecutive 'fyt', while 'ffyytt' has no 'fyt' as its substring.

Input

The first line contains an integer $$$n\ (1 \leq n \leq 10^6)$$$, indicating the length of the string.

The second line contains a single string consisting of three characters 'f', 'y', and 't', representing the string.

Output

Output a single integer indicating the number of consecutive 'fyt' in the input string.

Examples
Input
6
fytfyt
Output
2
Input
9
fytffyytt
Output
1