#include<bits/stdc++.h>
using namespace std;
int main() 
{
	double n,k,a=200,b,m=0;
	cin >> n >> k;
	b = n;
	while(a>n)
	{
		m++;
		a += k*0.01*a;
		n += b;
		if(m>20)
		{
			break;
		}
	}
	if(m>20)
	{
		cout << "Impossible";
	}
	else cout << m+1;
	return 0;
}

元首写的，不外传

#include<bits/stdc++.h>
using namespace std;
int main() 
{
	double	n,k,a=200,b,m=0;
	cin>>n>>k;
	b=n;
	while(a>n)
	{
		m++;
		a+=k*0.01*a;
		n+=b;
		if(m>20) break;
	}
	if(m>20) cout<<"Impossible";
	else cout<<m+1;
	return 0;
}