```
#include<iostream>
using namespace std;
int main()
{
    float len, area;
    cin>>len;
    area = len*len;
    cout<<area;
    return 0;
}
```
#include<iostream>
using namespace std;
int main()
{
    float len, area;
    cin>>len;
    area = len*len;
    cout<<area;
    return 0;
}