Score : 200 points
We have N squares assigned the numbers 1,2,3,\ldots,N. Each square has an integer written on it, and the integer written on Square i is a_i.
How many squares i satisfy both of the following conditions?
Input is given from Standard Input in the following format:
N a_1 a_2 \cdots a_N
Print the number of squares that satisfy both of the conditions.
5 1 3 4 5 7
2
15 13 76 46 15 50 98 93 77 31 43 84 90 6 24 14
3