#include <bits/stdc++.h>
using namespace std;
inline char gc() {
  static char buf[100000], *p1 = buf, *p2 = buf;
  return p1 == p2 && (p2 = (p1 = buf) + fread(buf, 1, 100000, stdin), p1 == p2)
             ? EOF
             : *p1++;
}
inline long long read() {
  long long x = 0;
  char ch = gc();
  bool positive = 1;
  for (; !isdigit(ch); ch = gc())
    if (ch == '-') positive = 0;
  for (; isdigit(ch); ch = gc()) x = x * 10 + ch - '0';
  return positive ? x : -x;
}
inline void write(long long a) {
  if (a < 0) {
    a = -a;
    putchar('-');
  }
  if (a >= 10) write(a / 10);
  putchar('0' + a % 10);
}
inline void writeln(long long a) {
  write(a);
  puts("");
}
inline void wri(long long a) {
  write(a);
  putchar(' ');
}
inline unsigned long long rnd() {
  return ((unsigned long long)rand() << 30 ^ rand()) << 4 | rand() % 4;
}
const int N = 1000005, M = 1 << 21 | 2;
const long long inf = 1e18;
long long sum[M], p;
vector<long long> v[M];
int a[N];
void push_up(int nod) {
  sum[nod] = sum[nod << 1] + sum[nod << 1 | 1];
  int sz = v[nod << 1].size() - 1;
  v[nod].resize(v[nod << 1].size() + v[nod << 1 | 1].size() - 1);
  unsigned dq = 1;
  for (int i = (int)(0); i <= (int)(sz); i++) {
    long long r = i == sz ? inf : v[nod << 1][i + 1],
              jb = sum[nod << 1] - i * p;
    r += jb;
    dq--;
    while (dq < v[nod << 1 | 1].size() && v[nod << 1 | 1][dq] < r) {
      v[nod][i + dq] = max(v[nod << 1][i], v[nod << 1 | 1][dq] - jb);
      dq++;
    }
  }
  v[nod][0] = -inf;
}
void build(int l, int r, int nod) {
  if (l == r) {
    v[nod].resize(2);
    v[nod][0] = -inf;
    v[nod][1] = p - a[l];
    sum[nod] = a[l];
    return;
  }
  int mid = (l + r) >> 1;
  build(l, mid, nod << 1);
  build(mid + 1, r, nod << 1 | 1);
  push_up(nod);
}
long long ask(int l, int r, int i, int j, long long x, int nod) {
  if (l == i && r == j) {
    return x + sum[nod] -
           (upper_bound(v[nod].begin(), v[nod].end(), x) - v[nod].begin() - 1) *
               p;
  }
  int mid = (l + r) >> 1;
  if (j <= mid)
    return ask(l, mid, i, j, x, nod << 1);
  else if (i > mid)
    return ask(mid + 1, r, i, j, x, nod << 1 | 1);
  else {
    return ask(mid + 1, r, mid + 1, j, ask(l, mid, i, mid, x, nod << 1),
               nod << 1 | 1);
  }
}
int main() {
  int n = read(), m = read();
  p = read();
  for (int i = (int)(1); i <= (int)(n); i++) a[i] = read();
  build(1, n, 1);
  while (m--) {
    int l = read(), r = read();
    writeln(ask(1, n, l, r, 0, 1));
  }
}
