#include<bits/stdc++.h> using namespace std; #define int long long void fun () { int n, k, m; cin >> n >> m >> k; vector<int> a(n + 1), b(m + 1); for (int i = 1; i <= n; i++) cin >> a[i]; for (int i = 1; i <= m; i++) cin >> b[i]; if (k > m) { cout << "Impossible\n"; return; } int s = 0, ans = 1e18; for (int i = 1; i <= n; i++) s += a[i]; if (k == 1) { if (s <= b[1] && b[1] >= n) ans = min(ans, b[1] - s); if (m >= 2 && s <= b[2] && b[2] >= n) ans = min(ans, b[2] - s); if (ans == 1e18) { cout << "Impossible\n"; return; } cout << (ans) << endl; return; } if (b[1] + b[2] >= 2 * n && b[1] + b[2] >= s) { if (b[1] >= n && b[2] >= n) { cout << b[1] + b[2] - s << endl; } else cout << "Impossible\n"; } else { cout << "Impossible\n"; } } signed main () { ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); int tt = 1; //cin >> tt; while (tt--) fun(); return 0; }