/**
 *  Author  : Pnictogen
 *  Task    :
 *  Algo    :
**/
#include <bits/stdc++.h>

#define endl          '\n'
#define sqr(x)        (x) * (x)
#define gcd(x,y)      __gcd(x,y)
#define lcm(x,y)      ((x/gcd(x,y)) * y)
#define sz(x)         (int)x.size()
#define all(x)        (x).begin(),(x).end()
#define rall(x)       (x).rbegin(),(x).rend()
#define prec(x)       fixed<<setprecision(x)
#define min3(a,b,c)   min(a,min(b,c))
#define max3(a,b,c)   max(a,max(b,c))
#define min4(a,b,c,d) min(a,min(b,min(c,d)))
#define max4(a,b,c,d) max(a,max(b,max(c,d)))
#define unsyncIO      ios_base::sync_with_stdio(false); cin.tie(nullptr)

using namespace std;
using ll = long long;
using db = double;
using ld = long double;
using ull = unsigned long long;

const ld PI = acos((ld) - 1);
const int MOD = 1e9 + 7;
const ll INF = 2e18 + 1;
const ld EPS = 1e-9;
const int MX = 2e5;

#ifdef LOCAL
#include"debug.h"
#else
#define debug(...)
#endif

ll containerSize(const vector <ll>& v, ll mid) {
	ll cnt = 0, deap = 0; debug(mid);

	for (int i = 0; i < sz(v); i++) {
		deap += v[i];
		if (deap == mid) {
			cnt++;
			deap = 0;
		} else if (deap > mid) {
			deap = v[i];
			cnt++;
			if (v[i] == v[sz(v) - 1]) cnt++;
		} else if (deap == v[sz(v) - 1]) cnt++;
	}
	debug(cnt);
	return cnt;
}

void solve(int cs) {
	ll n, m;	cin >> n >> m;
	vector <ll> v(n);
	for (int i = 0; i < n; i++) cin >> v[i];
	ll low = 1, high = 1e18, mid, ans, cnt;

	while (low <= high) {
		//debug(low, high);
		mid = low + ((high - low) / 2);
		cnt = containerSize(v, mid);
		if (cnt < m) high = mid - 1;
		else if (cnt > m) low = mid + 1;
		else {
			ans = mid;
			high = mid - 1;
		}

	}
	cout << "Case " << cs << ": " << ans << endl;
}

int main() {

#ifdef LOCAL
	clock_t tStart = clock();
	freopen("in.txt", "r", stdin);
	freopen("out.txt", "w", stdout);
#endif
	unsyncIO;

	int t = 1, cs = 1;	cin >> t;

	while (t--) {
		solve(cs++);
	}

#ifdef LOCAL
	cerr << "\nRuntime: " << (ld) (clock() - tStart) / CLOCKS_PER_SEC << " Seconds" << endl;
#endif
	return 0;
}