#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define elif else if
#define ull unsigned long long

int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);
//	freopen("auxiliary.in", "r", stdin);
//	freopen("auxiliary.out", "w", stdout);

	int h, w, n;
	cin>>h>>w>>n;
	int k, cs=0;
	int t=0;
	if(w<=h)
	{
		h--;
		t=1;
		if(w % 2==0)
		{
			k=w/2;
			cs=k*h;
		}
		if(w % 2==1)
		{
			k=(w+1)/2;
			cerr<<"k="<<k<<endl;
			if(h % 2==0)
			{
				cerr<<"h/2+1="<<h/2+1<<endl;
				cs=k*(h/2+1);
				cerr<<cs<<endl;
				cs+=(k-1)*(h-(h/2+1));

				cerr<<cs<<endl;
			}
			if(h % 2==1)
			{
				cs=k*((h+1)/2);
				cerr<<cs<<endl;
				cs+=(k-1)*(h-(h+1)/2);
				cerr<<cs<<endl;
			}
		}

	}
	else
	{
		w--;
		t=2;
		if(h % 2==0)
		{
			k=h/2;
			cerr<<"k="<<endl;
			cs=k*w;
		}
		if(h % 2==1)
		{
			k=(h+1)/2;
			if(w % 2==0)
			{

				cerr<<"w/2+1="<<w/2+1<<endl;
				cs=k*(w/2+1);

				cerr<<cs<<endl;
				cs+=(k-1)*(w-(w/2+1));
				cerr<<cs<<endl;
			}
			if(w % 2==1)
			{
				cs=k*((w+1)/2);
				cs+=(k-1)*(w-(w+1)/2);
			}
		}
	}
	cout<<cs<<endl;
	if(n>cs)
	{
		cout<<"Impossible";
		return 0;
	}
	for (int i=0; i<h; i++)
	{
		if
		for (int j=0; j<w; j++)
		{

		}
	}
	return 0;

}