#include<bits/stdc++.h>
using namespace std;
ifstream f1("cheating.in");
ofstream f2("cheating.out");
int n, k, l, i=1, br;
set<int> m;
int main(){
    f1 >> n >> k >> l;
    while(m.find(i)==m.end()){
        if(i==l){f2 << br << endl; return 0;}
        m.insert(i);
        i+=k;
        if(i>n)i%=n;
        br++;
    }
    f2 << "Impossible" << endl;
    return 0;
}