#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cmath>
#include <vector>
#include <cstring>
#include <set>
#ifdef _WIN32
#define getchar _getchar_nolock
#define putchar _putchar_nolock
#else
#define getchar getchar_unlocked
#define putchar putchar_unlocked
#endif
#define pll pair<ll,ll>
#define pld pair<ld,ld>
typedef long long ll;
typedef long double ld;
typedef __int128 i128;
namespace io {
using namespace std;
template <typename T> void debug (T x) {
cerr<<x<<'\n';
}
template <typename T> void debuglen (T x) {
cerr<<x<<' ';
}
template <typename T,typename...Args> void debug (T x,Args...args) {
cerr<<x<<' ';
debug(args...);
}
template <typename T> void debug (T*lt,T*rt) {
ll len=rt-lt;
for (ll i=0;i<len;i++) {
debuglen(*(lt+i));
}
cerr<<'\n';
}
inline ll read () {
char x=getchar();
ll ans=0,f=1;
while (x<'0'||x>'9') {
if (x=='-') {
f=-1;
}
x=getchar();
}
while (x>='0'&&x<='9') {
ans=(ans<<1)+(ans<<3);
ans+=(x^'0');
x=getchar();
}
return ans*f;
}
void print (ll x) {
if (x<0) {
x=-x;
putchar('-');
}
if (x>=10) {
print(x/10);
}
putchar(x%10+'0');
}
}
using namespace io;
const ll N=5e5+5,mod=1e9+7,inf=2e18;
const ld eps=1e-6;
ll n,q,k,a[N],sum[N],b[N],f[N][20],g[N][20];
set<pll> st;
inline void calc (ll l,ll r,ll num) {
auto it=st.lower_bound({l,0});
while (it!=st.end()&&(*it).first<=r) {
f[(*it).second][0]=num+1;
it=st.erase(it);
}
}
inline void solve () {
n=read(),q=read(),k=read();
for (ll i=1;i<=n;i++) {
a[i]=read();
if (!(i&1)) {
a[i]=-a[i];
}
sum[i]=sum[i-1]+a[i];
b[i]=(sum[i]%k+k)%k;
}
for (ll i=1;i<=n;i+=2) {
f[i][0]=n+1;
}
for (ll i=2;i<=n;i+=2) {
f[i][0]=i+1;
st.insert({b[i-2],i-1});
calc(b[i-1]+a[i]+1,b[i-1],i);
calc(max(b[i-1]+a[i]+k,b[i-1])+1,k-1,i);
}
for (ll i=1;i<=n;i+=2) {
ll num=sum[f[i][0]-2]-sum[i-1];
if (f[i][0]==n+1&&n&1) {
num+=a[n];
}
g[i][0]=num/k;
}
ll kl=-1,pl=n;
while (pl) {
pl>>=1;
kl++;
}
for (ll i=1;i<=kl;i++) {
for (ll j=1;j<=n-(1<<i)+1;j++) {
f[j][i]=f[f[j][i-1]][i-1];
g[j][i]=g[j][i-1]+g[f[j][i-1]][i-1];
}
}
while(q--) {
ll x=read(),y=read();
ll ans=0;
kl=-1,pl=y-x+1;
while (pl) {
pl>>=1;
kl++;
}
for(ll i=kl;i>=0;i--) {
if(f[x][i]>y||!f[x][i]) {
continue;
}
ans+=g[x][i];
x=f[x][i];
}
ll num=sum[y]-sum[x-1];
if (!(x&1)) {
num-=a[x];
}
if (x!=y&&!(y&1)) {
num-=a[y];
}
ans+=num/k;
print(ans);
puts("");
}
}
int main () {
// freopen(".in","r",stdin);
// freopen(".out","w",stdout);
ll T=1;
// T=read();
while (T--) {
solve();
}
return 0;
}
