#include "bits/stdc++.h"
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
typedef tree<pair<int, int>, null_type, less<pair<int,int>>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;
#define ll long long
#define mod 1000000007
ofstream fout(".out");
ifstream fin(".in");
signed main() {
ios::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
int n, m, k;
cin >> n >> m >> k;
int a[n], b[m];
int x = 0;
for(int i = 0; i < n; i++) {
cin >> a[i];
x += a[i];
}
int y = 0;
for(int i = 0; i < m; i++) {
cin >> b[i];
y += b[i];
}
if(m == 1 && k == 1 && y >= x) {
cout << y - x;
return 0;
}
if(m == 2) {
if(b[0] > b[1])
swap(b[0], b[1]);
if(k == 1) {
if(b[0] >= x) {
cout << b[0] - x;
return 0;
}
if(b[1] >= x) {
cout << b[1] - x;
return 0;
}
if(y >= x) {
cout << y - x;
return 0;
}
}
else if(k == 2) {
if(y >= x && b[0] >= n) {
cout << y - x;
return 0;
}
}
}
cout << "Impossible";
return 0;
}
