ソースコード
#include<bits/stdc++.h>
#define rep(i,a,b) for(int i=a;i<b;i++)
#define rrep(i,a,b) for(int i=a;i>=b;i--)
#define fore(i,a) for(auto &i:a)
#define all(x) (x).begin(),(x).end()
#pragma GCC optimize ("-O3")
using namespace std; void _main(); int main() { cin.tie(0); ios::sync_with_stdio(false); _main(); }
typedef long long ll; const int inf = INT_MAX / 2; const ll infl = 1LL << 60;
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a = b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a = b; return 1; } return 0; }
//---------------------------------------------------------------------------------------------------
/*---------------------------------------------------------------------------------------------------
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∧＿∧ （´<_｀ ） Welcome to My Coding Space!
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＼/＿＿＿＿/ （u ⊃
---------------------------------------------------------------------------------------------------*/
int N, K, B, A[16];
int dp[20][1 << 16], f[1<<16];
//---------------------------------------------------------------------------------------------------
int solve(int gr, int msk) {
if (msk == 0 and 1 <= gr) return inf;
if (gr == 0) {
if (msk == 0) return 0;
else return inf;
}
if (gr == 1) return f[msk];
if (dp[gr][msk] < inf) return dp[gr][msk];
int a = gr / 2;
int b = gr - a;
for (int msk2 = msk; msk2 >= 0; msk2--) {
msk2 &= msk;
chmin(dp[gr][msk], solve(a, msk2) + solve(b, msk - msk2));
}
return dp[gr][msk];
}
//---------------------------------------------------------------------------------------------------
void _main() {
cin >> N >> K >> B;
rep(i, 0, N) cin >> A[i];
rep(gr, 0, N + 1) rep(msk, 0, 1 << N) dp[gr][msk] = inf;
rep(msk, 0, 1 << N) {
int sm = 0;
rep(i, 0, N) if (msk & (1 << i)) sm += A[i];
f[msk] = (sm + B - 1) / B;
}
int ma = -1;
rep(gr, 1, N + 1) if (solve(gr, (1 << N) - 1) <= K) chmax(ma, gr);
int ans = N - ma;
cout << ans << endl;
}