#include <iostream>
 #include <cmath>
 using namespace std;
 
 int lifanghe[14] = {0, 1, 9, 36, 100, 225, 441, 784, 1296, 2025, 3025, 4356, 6084, 8281};
 int pingfanghe[14] = {0, 1, 5, 14, 30, 55, 91, 140, 204, 285, 385, 506, 650, 819};
 
 int N, M;
 int remN, alrM;
 
 int MIN = 2147483647;
 
 int mx(int a, int b){
	if(a<b) return b;
	return a;
 }
 
 int mn(int a, int b){
 	if(a>b) return b;
 	return a;
 }
 
 void dfs(int maxR, int maxH, int m){
 	//cout << maxR << " " << maxH << " " << m << endl;
 	if(m == 0){
 		if(remN == 0){
 			MIN = mn(MIN, alrM);
 		}
		return; 	}
 	if(m == 1){
 		for(int r = maxR; r >= 1; r--){
 			int h = remN / r / r;
 			if(r * r * h == remN && h > 0 && h <= maxH){
 				int res = alrM + 2 * h * r;
 				if(res < MIN) MIN = res;
 			}
 		}
 		return;
 	}
 	int maxR2H = remN - lifanghe[m-1];
 	int maxr = (int)sqrt(0.1 + maxR2H * 1.0 / m);
 	maxr = mn(maxR, maxr);
 	for(int R = maxr; R >= m; R--){
 		int maxh = mn(maxH, maxR2H / (R * R));
 		for(int H = maxh; H >= m; H--){
 			bool can = false;
 			int maxSum = 0;
 			for(int i = 0; i < m; i++){
> 				maxSum += (R-i)*(R-i)*(H-i);
> 				if(maxSum >= remN){
> 					can = true;
> 					break;
> 				}
> 			}
> 			if(!can) break;
> 			int newremN = remN - R*R*H;
> 			int newalrM = alrM + 2*R*H;
> 			if(newalrM + 2 * pingfanghe[m-1] >= MIN) continue;
> 			if(newalrM + 2 * ((newremN + (m==2? 0: 1))/(R-1)) >= MIN) continue;
> 			remN = newremN;
> 			alrM = newalrM;
> 			dfs(R-1, H-1, m-1);
> 			remN += R*R*H;
> 			alrM -= 2*R*H;
> 		}
> 	}
> }
> 
> int main() {
> 
> 	cin >> N >> M;
> 	if(M >= 14 || lifanghe[M] > N){
> 		cout << 0 << endl;
> 		return 0;
> 	}
> 	remN = N;
> 	alrM = 0;
> 	int maxR2H = N - lifanghe[M-1];
> 	int maxR = (int)sqrt(0.1 + maxR2H * 1.0 / M);
> 	//bool daCan = true;
> 	for(int R = maxR; R >= M; R --){
> 		int maxH = maxR2H / (R*R);
> 		for(int H = maxH; H >= M; H--){
> 			bool can = false;
> 			int maxSum = 0;
> 			for(int i = 0; i < M; i++){
> 				maxSum += (R-i)*(R-i)*(H-i);
> 				if(maxSum >= N){
> 					can = true;
> 					break;
> 				}
> 			}
> 			if(!can) {
> 				break;
> 			}
> 			remN = N - R*R*H;
> 			alrM = R*R + 2*H*R;
> 			if(alrM + 2 * pingfanghe[M-1] >= MIN) continue;
> 			//cout << 1 << endl;
> 			if(M > 1 && alrM + 2 * ((remN + (M==2 ? 0: 1)) / (R - 1)) >= MIN) continue;
> 			dfs(R-1, H-1, M-1);
> 			remN = N;
> 			alrM = 0;
> 		}
> 	}
> 	if(MIN == 2147483647) cout << 0 << endl;
> 	else cout << MIN << endl;
> 	return 0;
> }