#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); int s = 0, s1 = 0; for (int i = 1; i <= n; i++) cin >> a[i], s += a[i]; for (int i = 1; i <= m; i++) cin >> b[i], s1 += b[i]; vector<vector<int>> dp(m + 1, vector<int>(s1 + 1)); for (int i = 1; i <= m; i++) { for (int j = 0; j <= s1; j++) { if (j - b[i] >= 0) { dp[i][j] = dp[i - 1][j - b[i]] + min(b[i], n); } dp[i][j] = max(dp[i][j], dp[i - 1][j]); } } for (int i = s; i <= s1; i++) { if (dp[m][i] >= n * k) { cout << i - s << endl; return; } } cout << "Impossible"; } signed main () { ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); int tt = 1; //cin >> tt; while (tt--) fun(); return 0; }