#include<iostream>
#include<cstdio>
#include<map>
#define endl '\n'
using namespace std;
typedef long long ll;
ll n,k,i,j,p,q,l,br;
map <ll,bool> b;
int main()
{
    freopen("cheating.in", "r", stdin);
    freopen("cheating.out", "w", stdout);
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    cin>>n>>k>>l;
    if(k==1)
    {
        cout<<l-1<<endl;
    }
    else if(n%k==0)
    {
        if(l%k==1)
        {
            cout<<l/k<<endl;
        }
        else
            cout<<"Impossible"<<endl;
    }
    else
    {
        p = 1;
        b[p] = 1;
        while(1)
        {
            p+=k;
            if(p>n)p-=n;
            br++;
            if(b[p]==0)
            {
                b[p] = 1;
            }
            else
            {
                break;
            }
            if(p==l)
            {
                cout<<br;
                return 0;
            }

        }
        cout<<"Impossible";
    }
    return 0;

}