#include <bits/stdc++.h>
#pragma comment(linker, "/STACK:66777216")
#pragma hdrstop
using namespace std;
inline void sIO() {}
inline void iIO() {
  freopen("input.txt", "r", stdin);
  freopen("output.txt", "w", stdout);
}
inline void fIO(string fn) {
  freopen((fn + ".in").c_str(), "r", stdin);
  freopen((fn + ".out").c_str(), "w", stdout);
}
inline void TM() {}
inline void swap(short& a, short& b) { b ^= a ^= b ^= a; }
inline void swap(int& a, int& b) { b ^= a ^= b ^= a; }
inline void swap(char& a, char& b) { b ^= a ^= b ^= a; }
inline void swap(long long& a, long long& b) { b ^= a ^= b ^= a; }
template <class T>
inline T abs(T x) {
  return x < 0 ? -x : x;
}
template <class T>
inline T sqr(T x) {
  return x * x;
}
template <class T>
inline T min(T& a, T& b) {
  return a < b ? a : b;
}
template <class T>
inline T max(T& a, T& b) {
  return a > b ? a : b;
}
template <class T>
inline T gcd(T a, T b) {
  if (a < b) swap(a, b);
  while (b) {
    a %= b;
    swap(a, b);
  }
  return a;
}
template <class T>
inline T lcm(T a, T b) {
  return a / gcd(a, b) * b;
}
template <class T>
inline bool isPrime(T n) {
  if (n < 2) return false;
  T kk = (T)sqrt(n + 0.);
  for (T i = 2; i <= kk; ++i)
    if (!(n % i)) return false;
  return true;
}
template <class T>
inline string toa(T x) {
  stringstream ss;
  ss << x;
  string ret;
  ss >> ret;
  return ret;
}
template <class T>
inline T ppow(T a, long long b) {
  T ret = 1;
  while (b) {
    if (b & 1) ret *= a;
    a *= a;
    b >>= 1;
  }
  return ret;
}
template <class T>
inline T ppow(T a, long long b, long long md) {
  T ret = 1;
  a %= md;
  while (b) {
    if (b & 1) ret = ret * a % md;
    a = a * a % md;
    b >>= 1;
  }
  return ret % md;
}
inline int toi(string s) {
  stringstream ss;
  ss << s;
  int ret;
  ss >> ret;
  return ret;
}
inline long long tol(string s) {
  stringstream ss;
  ss << s;
  long long ret;
  ss >> ret;
  return ret;
}
inline int Random() { return ((rand() << 16) | rand()); }
inline char upperCase(char ch) {
  return (ch >= 'a' && ch <= 'z') ? ch ^ 32 : ch;
}
inline char lowerCase(char ch) {
  return (ch >= 'A' && ch <= 'Z') ? ch ^ 32 : ch;
}
inline string upperCase(string s) {
  int ls = s.length();
  for (int i = 0; i < ls; ++i)
    if (s[i] >= 'a' && s[i] <= 'z') s[i] ^= 32;
  return s;
}
inline string lowerCase(string s) {
  int ls = s.length();
  for (int i = 0; i < ls; ++i)
    if (s[i] >= 'A' && s[i] <= 'Z') s[i] ^= 32;
  return s;
}
inline int dig(char ch) { return ch - 48; }
inline bool isAlpha(char ch) {
  return (ch >= 'A' && ch <= 'Z' || ch >= 'a' && ch <= 'z');
}
inline bool isDigit(char ch) { return (ch >= '0' && ch <= '9'); }
inline bool isLowerCase(char ch) { return (ch >= 'a' && ch <= 'z'); }
inline bool isUpperCase(char ch) { return (ch >= 'A' && ch <= 'Z'); }
int __;
const int INF = 0x3f3f3f3f;
const long long LINF = 0x3f3f3f3f3f3f3f3fLL;
const double EPS = 1e-9;
const int MD = 1000000007;
int n, c[111111], mx1, mx2, col[111111], tmp;
long long ans, d[111111], x, y, v[111111], cur;
int main() {
  sIO();
  scanf("%d%d", &n, &__);
  for (int i = 0; i < n; ++i) scanf("%lld", v + i);
  for (int i = 0; i < n; ++i) scanf("%d", c + i);
  for (int _ = 0; _ < __; ++_) {
    scanf(
        "%lld"
        "%lld",
        &x, &y);
    memset(d, 0, sizeof(d));
    memset(col, -1, sizeof(col));
    d[0] = v[0] * y;
    col[c[0]] = 0;
    mx1 = 0;
    mx2 = -1;
    for (int i = 1; i < n; ++i) {
      cur = v[i] * y;
      if ((tmp = col[c[i]]) >= 0) cur = max(cur, d[tmp] + v[i] * x);
      if (c[mx1] != c[i])
        cur = max(cur, d[mx1] + v[i] * y);
      else if (mx2 >= 0)
        cur = max(cur, d[mx2] + v[i] * y);
      d[i] = cur;
      if (cur >= d[mx1]) {
        if (c[mx1] != c[i]) mx2 = mx1;
        mx1 = i;
      } else if (cur > d[mx2] && c[mx1] != c[i])
        mx2 = i;
      if (tmp == -1 || d[tmp] < d[i]) col[c[i]] = i;
    }
    printf(
        "%lld"
        "\n",
        max(0LL, d[mx1]));
  }
  return 0;
}
