#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef unsigned long long ull;
#define int ll
#define PI acos(-1.0)
#define INF 0x3f3f3f3f3f3f3f3f
#define P pair<int, int>
#define fastio ios::sync_with_stdio(false), cin.tie(0)
const int mod = 1e9 + 7;
const int M = 1000000 + 10;
const int N = 100000 + 10;

long long mulmod(long long n, long long m)
{
    n %= mod, m %= mod;
    return (n * m - (long long)((long double)n / mod * m) * mod + mod) % mod;
}

int powmod(int n, int m)
{
    int ans = 1;
    while(m) {
        if(m & 1) ans = mulmod(ans, n) % mod;
        n = mulmod(n, n) % mod;
        m >>= 1;
    }
    return ans % mod;
}

int n, q, b;
int tree[N<<2], add[N<<2];
int pow_q[N], inv;

int sum(int a1, int num)
{
    return mulmod(mulmod(a1, (pow_q[num] - 1)), inv);
}

void build(int l = 1, int r = n, int rt = 1)
{
    if(l == r) {
        scanf("%lld", &tree[rt]);
        return ;
    }
    int mid = (l + r) >> 1;
    build(l, mid, rt << 1);
    build(mid + 1, r, rt << 1 | 1);
    tree[rt] = (tree[rt << 1] + tree[rt << 1 | 1]) % mod;
}

void push(int l, int r, int rt)
{
    if(add[rt]) {
        int mid = (l + r) >> 1, temp;
        add[rt << 1] = (add[rt << 1] + add[rt]) % mod;
        add[rt << 1 | 1] = (add[rt << 1 | 1] + (temp = add[rt] * pow_q[mid - l + 1] % mod)) % mod;
        tree[rt << 1] = (tree[rt << 1] + sum(add[rt], mid - l + 1)) % mod;
        tree[rt << 1 | 1] = (tree[rt << 1 | 1] + sum(temp, r - mid)) % mod;
        add[rt] = 0;
    }
}

void update(int L, int R, int l = 1, int r = n, int rt = 1)
{
    if(L <= l && r <= R) {
        int a1 = pow_q[l - L];
        tree[rt] = (tree[rt] + sum(a1, r - l + 1)) % mod;
        add[rt] += a1;
        return ;
    }
    push(l, r, rt);
    int mid = (l + r) >> 1;
    if(L <= mid) update(L, R, l, mid, rt << 1);
    if(mid < R) update(L, R, mid + 1, r, rt << 1 | 1);
    tree[rt] = (tree[rt << 1] + tree[rt << 1 | 1]) % mod;
}

int query(int L, int R, int l = 1, int r = n, int rt = 1)
{
    if(L <= l && r <= R) return tree[rt];
    push(l, r, rt);
    int mid = (l + r) >> 1, ans = 0;
    if(L <= mid) ans = (ans + query(L, R, l, mid, rt << 1)) % mod;
    if(mid < R) ans = (ans + query(L, R, mid + 1, r, rt << 1 | 1)) % mod;
    return ans;
}

void pre()
{
    inv = powmod(b - 1, mod - 2);
    pow_q[0] = 1;
    for(int i = 1; i <= n; i ++) {
        pow_q[i] = pow_q[i - 1] * b % mod;
    }
    build();
}

signed main()
{
    freopen("in.in", "r", stdin);
    freopen("txb.out", "w", stdout);
    scanf("%lld %lld %lld", &n, &q, &b);
    pre();