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

const int MAXN = 4e5 + 5;

typedef long long ll;

int n, m, k, a[MAXN];

ll len[MAXN];

inline int askLen(int l, int r) {
    return len[r] - len[l - 1];
}

#define ls x << 1
#define rs x << 1 | 1

ll sum[MAXN << 2];
int t[MAXN << 2];

inline void pushr(int x, int l, int r) {
    sum[x] = askLen(l, r), t[x] = 1;   
}

inline void pushdown(int x, int l, int r) {
    if(t[x]) {
        int mid = l + r >> 1;
        pushr(ls, l, mid);
        pushr(rs, mid + 1, r);
        t[x] = 0;
    }
}

void pushup(int x) {
    sum[x] = sum[ls] + sum[rs]; 
}

inline int ask(int x, int l, int r, int ql, int qr) {
    if(ql > qr) return 0; 
    if(ql <= l && r <= qr) { return sum[x];}
    pushdown(x, l, r);
    int mid = l + r >> 1;
    if(qr <= mid) return ask(ls, l, mid, ql, qr);
    else if(ql > mid) return ask(rs, mid + 1, r, ql, qr);
    else return ask(ls, l, mid, ql, qr) + ask(rs, mid + 1, r, ql, qr);
}

inline void push(int x, int l, int r, int ql, int qr) {
    if(ql > qr) return ;
    if(ql <= l && r <= qr) return pushr(x, l, r);
    pushdown(x, l, r);
    int mid = l + r >> 1;
    if(qr <= mid)  push(ls, l, mid, ql, qr);
    else if(ql > mid) push(rs, mid + 1, r, ql, qr);
    else push(ls, l, mid, ql, qr), push(rs, mid + 1, r, ql, qr);
    pushup(x);
}

inline void add(int x, int l, int r, int p, int v) {
    if(l == r) {
        sum[x] += v;
        return ;
    }
    pushdown(x, l, r);
    int mid = l + r >> 1;
    if(p <= mid) add(ls, l, mid, p, v);
    else add(rs, mid + 1, r, p, v);
    pushup(x);
}

inline void upd(int L, int R) {
    // cout << L << ' ' << R << '\n';
    int ans = R + 1, l = L, r = R;
    while(l <= r) {
        int mid = l + r >> 1;
        if(askLen(mid, R) + ask(1, 1, n + m - 1, L, mid - 1) <= k) {
            ans = mid, r = mid - 1; 
        } else l = mid + 1;
    }
    // cout << ans << ' ' << sum[1] << '\n';
    push(1, 1, n + m - 1, ans, R);
    int t = ask(1, 1, n + m - 1, L, R);
    if (ans - 1 >= L) {
        int p = k - ask(1, 1, n + m - 1, L, R);
        // cout << ans - 1 << ' ' << p << "xxx\n";
        if(p > 0) add(1, 1, n + m - 1, ans - 1, p);
    }
}

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
    cin >> n >> m >> k;
    for (int i = 1; i <= n; i++) 
        cin >> a[i], len[i] = len[i - 1] + a[i];
    for(int i = n + 1; i <= n + m - 1; i++) 
        len[i] = len[i - 1];
    for (int i = 1; i <= n + m - 1; i++) {
        upd(max(i - m + 1, 1), i);
        // for(int j = 1; j <= n; j++) {
        //     cout << ask(1, 1, n + m - 1, j, j) << ' ';
        // }
        // cout << '\n';
    }
    cout << sum[1] << '\n';
    return 0;
}
/*
8 3 2
3
1
4
1
5
9
2
6
*/