#include <iostream> #include <bitset> #include <algorithm> using namespace std; const int N = 305, NN = 90005; bitset<90005> bt[N], Bt; int a[N], b[N]; int main(){ int n, m, k, Ans = NN, ex = 0; cin>>n>>m>>k; for (int i=1;i<=n;i++) cin>>a[i]; for (int j=1;j<=m;j++) cin>>b[j]; sort(b + 1, b + m + 1); for (int i=1;i<=n;i++){ if (a[i] < k) return cout<<"Impossible\n", 0; ex += a[i] - k; } Bt[0] = bt[0][0] = 1; for (int i=1;b[i] < n;i++) Bt |= Bt << b[i]; for (int i=m;b[i] >= n;i--){ for (int j=min(m - i + 1, k);j>=1;j--) bt[j] |= (bt[j-1] << (b[i] - n)) | (bt[i] << b[i]); } for (int i=k;i>=0;i--){ for (int j=NN-1, l = 0;j>=0;j--){ while (j >= 0 and bt[i][j] == 0) j--; while (j >= 0 and l < N and (Bt[l] == 0 or j + l < ex)) l++; if (j >= 0 and l < N) Ans = min(Ans, j + l - ex); } Bt >>= n; } if (Ans == NN) cout<<"Impossible\n"; else cout<<Ans<<'\n'; }