o61_mar_c2_chickentart

#include <bits/stdc++.h>

using namespace std;
const int INF = 1e9;
const int N = 1e5 + 10;
int ar[N], qsL[N], qsR[N];
int n, m, k;

bool check(int limit){

    int MinPst = INF, MaxPst = -INF;
    for(int i=1;i<=n;i++)
        if(ar[i] > limit) MinPst = min(MinPst, i), MaxPst = max(MaxPst, i);
    if(MinPst != INF and MaxPst != -INF and MaxPst - MinPst + 1 > m) return false;

    /// [1, MinPst) + (MaxPst, n]

    if(MinPst != 1){
        qsL[1] = 1;
        int SumL = ar[1], cntL = 1, preL = 1;
        for(int i = 2; i < min(MinPst, n+1); i ++){
            if(SumL + ar[i] <= limit and i - preL + 1 <= m) SumL += ar[i];
            else SumL = ar[i], cntL ++, preL = i;
            qsL[i] = cntL;
        }
    }

    if(MaxPst != n){
        qsR[n] = 1;
        int SumR = ar[n], cntR = 1, preR = n;
        for(int i = n-1; i > max(MaxPst, 0); i --){
            if(SumR + ar[i] <= limit and preR - i + 1 <= m) SumR += ar[i];
            else SumR = ar[i], cntR ++, preR = i;
            qsR[i] = cntR;
        }
    }

    /// m = len
    int st = max(1, MaxPst - m + 1), ed = min(st + m - 1, n);
    while(st <= MinPst and ed <= n){
        if(qsL[st-1] + qsR[ed+1] < k) return true;
        st ++, ed ++;
    }

    return false;
}

int main(){

    scanf("%d%d%d", &n, &m, &k);

    for(int i=1;i<=n;i++)
        scanf("%d", &ar[i]);

    int l = 0, r = INF, mn = INF;
    while(l <= r){
        int mid = (l + r) / 2;
        bool ch = check(mid);
        if(ch){
            r = mid - 1;
            mn = min(mn, mid);
        }
        else
            l = mid + 1;
    }

    printf("%d", mn);

    return 0;

}