Small bulbs b and 51nod 2489

B has n small bulb closed, numbered 1 ... n.

B n-th wheel will be small operation, the i-th round she will numbered multiple of the switching status of the lamp i negated, i.e., turned-open, closed into open.

After the n-th wheel required operation, how much the bulb is on.

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Entry

A lamp input number indicates the number of n, where 1 <n≤10000000

Export

A number indicates the final output of the lamp lit

SAMPLE INPUT

3

Sample Output

1 

water. . 
Code:

#include <iostream>
#include <cstdlib>
#include <cstdio>
#include <cmath>

using namespace std;

int main() {
    int n;
    scanf("%d",&n);
    printf("%d",int(sqrt(n)));
    return 0;
}