#include<bits/stdc++.h>
#define ll long long
#define db double
#define ull unsigned long long
#define pb push_back
#define pii pair<int, int>
#define FR first
#define SE second
#define int long long
using namespace std;
inline int read() {
  int x = 0; bool op = false;
  char c = getchar();
  while(!isdigit(c))op |= (c == '-'), c = getchar();
  while(isdigit(c))x = (x << 1) + (x << 3) + (c ^ 48), c = getchar();
  return op ? -x : x;
}
const int N = 5e5 + 10;
const int INF = 1e18;
int n, m, x;
int a[N], b[N], c[N], d[N];
signed main() {
  n = read(); m = read(); x = read();
  for(int i = 1; i <= n; i++)a[i] = read();
  for(int i = 1; i <= m; i++)b[i] = read();
  int cnt1 = 0, cnt2 = 0;
  int mn1 = INF, mn2 = INF;
  for(int i = 1; i <= n; i++)mn1 = min(mn1, a[i]);
  for(int i = 1; i <= m; i++)mn2 = min(mn2, b[i]);
  for(int i = 1; i <= n; i++)a[i] -= mn1;
  for(int i = 1; i <= m; i++)b[i] -= mn2;
  for(int i = 1; i <= n; i++)cnt1 += a[i] / x, a[i] %= x;
  for(int i = 1; i <= m; i++)cnt2 += b[i] / x, b[i] %= x;
  sort(a + 1, a + 1 + n); sort(b + 1, b + 1 + m);
  int g = __gcd(n, m), ans = INF;
  // printf("%d %d\n", cnt1, cnt2);
  // for(int i = 1; i <= n; i++)printf("%d ", a[i]); putchar('\n');
  // for(int i = 1; i <= m; i++)printf("%d ", b[i]); putchar('\n');
  for(int i = 0; i < g; i++)c[i] = d[i] = INF;
  for(int i = 1; i <= n; i++) {
    int &v = c[((i - cnt1) % g + g) % g];
    v = min(v, x - (a[i % n + 1] - a[i] + (i == n) * x));
  }
  for(int i = 1; i <= m; i++) {
    int &v = d[((i - cnt2) % g + g) % g];
    v = min(v, x - (b[i % m + 1] - b[i] + (i == m) * x));
  }
  for(int i = 0; i < g; i++)ans = min(ans, c[i] + d[i]);
  // for(int i = 1; i <= n; i++) {
  //   for(int j = 1; j <= m; j++) {
  //     int val = (i - cnt1) - (j - cnt2);
  //     val = (val % g + g) % g;
  //     if(val == 0)ans = min(ans, 2 * x - (a[i % n + 1] - a[i] + x) % x - (b[j % m + 1] - b[j] + x) % x);
  //   }
  // }
  printf("%lld\n", ans); 
  return 0;
}