#include <bits/stdc++.h> using namespace std; const int N = 310; int a[N], b[N]; int sum_a; int main(){ ios_base::sync_with_stdio(false); cin.tie(nullptr); int n, m, k; cin >> n >> m >> k; if(m < k) { cout << "Impossible\n"; return 0; } for(int i = 0; i < n; ++i){ cin >> a[i]; if(k > a[i]) { cout << "Impossible\n"; return 0; } sum_a += a[i]; } for(int i = 0; i < m; ++i){ cin >> b[i]; } int ans = 0; if(k == 1){ if(b[0] >= sum_a) cout << b[0] - sum_a; else if(b[1] >= sum_a) cout << b[1] - sum_a; else if(b[0]+b[1] >= sum_a) cout << b[0]+b[1] - sum_a; else{ cout << "Impossible\n"; return 0; } }else{ if(b[0]+b[1] >= sum_a) cout << b[0]+b[1]-sum_a; else{ cout << "Impossible\n"; return 0; } } }