There are n student groups at the university. During the study day, each group can take no more than 7 classes. Seven time slots numbered from 1 to 7 are allocated for the classes.

The schedule on Monday is known for each group, i. e. time slots when group will have classes are known.

Your task is to determine the minimum number of rooms needed to hold classes for all groups on Monday. Note that one room can hold at most one group class in a single time slot.

Input

The first line contains a single integer n (1 ≤ n ≤ 1000) — the number of groups. 

Each of the following n lines contains a sequence consisting of 7 zeroes and ones — the schedule of classes on Monday for a group. If the symbol in a position equals to 1 then the group has class in the corresponding time slot. In the other case, the group has no class in the corresponding time slot.

Output

Print minimum number of rooms needed to hold all groups classes on Monday.

Examples

Input

2
0101010
1010101


Output

1


Input

3
0101011
0011001
0110111


Output

3

Note

In the first example one room is enough. It will be occupied in each of the seven time slot by the first group or by the second group.

In the second example three rooms is enough, because in the seventh time slot all three groups have classes.
import java.util.*;
import java.io.*;
import java.math.*;

public class G{
	
	static int n,c[]=new int[7];
	static void MainMethod()throws Exception{
		n=reader.nextInt();
		String s;
		int i,j;
		Arrays.fill(c, 0);
		for (i=0;i<n;i++) {
			s=reader.next();
			for (j=0;j<7;j++)
				c[j]+=(s.charAt(j)-'0');
		}
		int res=0;
		for (i=0;i<7;i++)res=Math.max(res, c[i]);
		printer.println(res);
	}
	public static void main(String[] args)throws Exception{
		MainMethod();
		printer.close();
	}
	static void halt(){
		printer.close();
		System.exit(0);
	}
	static PrintWriter printer=new PrintWriter(new OutputStreamWriter(System.out));
	static class reader{
		static BufferedReader bReader=new BufferedReader(new InputStreamReader(System.in));
		static StringTokenizer token=new StringTokenizer("");
		static String readNextLine() throws Exception{
			return bReader.readLine();
		}
		static String next() throws Exception{
			while (token.hasMoreTokens()==false){
				token=new StringTokenizer(bReader.readLine());
			}
			return token.nextToken();
		}
		static int nextInt()throws Exception{
			while (token.hasMoreTokens()==false){
				token=new StringTokenizer(bReader.readLine());
			}
			return Integer.parseInt(token.nextToken());
		}
		static long nextLong()throws Exception{
			while (token.hasMoreTokens()==false){
				token=new StringTokenizer(bReader.readLine());
			}
			return Long.parseLong(token.nextToken());
		}
		static double nextDouble()throws Exception{
			while (token.hasMoreTokens()==false){
				token=new StringTokenizer(bReader.readLine());
			}
			return Double.parseDouble(token.nextToken());
		}
	}
	static class MyMathCompute{
		static long [][] MatrixMultiplyMatrix(long [][] A, long [][] B, long mod) throws Exception{
			int n=A.length, m=B[0].length; 
			int p=A[0].length;
			int i,j,k;
			if (B.length!=p) throw new Exception("invalid matrix input");
			long [][] res=new long [n][m];
			for (i=0;i<n;i++) for (j=0;j<m;j++){
				if (A[i].length!=p) throw new Exception("invalid matrix input");
				res[i][j]=0;
				for (k=0;k<p;k++)
					res[i][j]=(res[i][j]+((A[i][k]*B[k][j])% mod))% mod;
			}
			return res;
		}
		static double [][] MatrixMultiplyMatrix(double [][] A, double [][] B ) throws Exception{
			int n=A.length, m=B[0].length; 
			int p=A[0].length;
			int i,j,k;
			if (B.length!=p) throw new Exception("invalid matrix input");
			double [][] res=new double [n][m];
			for (i=0;i<n;i++) for (j=0;j<m;j++){
				if (A[i].length!=p) throw new Exception("invalid matrix input");
				res[i][j]=0;
				for (k=0;k<p;k++)
					res[i][j]=res[i][j]+(A[i][k]*B[k][j]);
			}
			return res;
		}
		static long [][] MatrixPow(long [][] A,long n, long mod) throws Exception{
			if (n==1) return A;
			long [][] res=MatrixPow(A, n/2, mod);
			res=MatrixMultiplyMatrix(res, res, mod);
			if ((n % 2) == 1) res=MatrixMultiplyMatrix(A,res, mod);		
			return res;
		}
		static double [][] MatrixPow(double [][] A,long n) throws Exception{
			if (n==1) return A;
			double[][] res=MatrixPow(A, n/2);
			res=MatrixMultiplyMatrix(res, res);
			if ((n % 2) == 1) res=MatrixMultiplyMatrix(A,res);		
			return res;
		}
		static long pow(long a,long n,long mod){
			a= a % mod;
			if (n==0) return 1;
			long k=pow(a,n/2,mod);
			if ((n % 2)==0) return ((k*k)%mod);
			else return (((k*k) % mod)*a) % mod;
		}
		static double pow(double a,long n){
			if (n==0) return 1;
			double k=pow(a,n/2);
			if ((n % 2)==0) return (k*k);
			else return (((k*k) )*a) ;
		}
	}
}
