n,d=map(int,input().split())
x=y=0
for i in range(d):
if '0' in input():
x+=1
else:
x=0
y=max(x,y)
print(y)#include <bits/stdc++.h>
using namespace std;
int main(){
int n,d;
cin>>n>>d;
int count = 0;
int maxcount = 0;
bool contin = true;
string a;
for(int i = 0;i<d;i++){
cin>>a;
for(int i = 0;i<n;i++){
if(a[i] != '1'){
contin = false;
break;
}
}
if(!contin){
count++;
}else{
maxcount = max(count,maxcount);
count = 0;
}
contin = true;
}
maxcount = max(count,maxcount);
cout<<maxcount<<endl;
}2B - The least round way | 1324A - Yet Another Tetris Problem |
246B - Increase and Decrease | 22E - Scheme |
1566A - Median Maximization | 1278A - Shuffle Hashing |
1666F - Fancy Stack | 1354A - Alarm Clock |
1543B - Customising the Track | 1337A - Ichihime and Triangle |
1366A - Shovels and Swords | 919A - Supermarket |
630C - Lucky Numbers | 1208B - Uniqueness |
1384A - Common Prefixes | 371A - K-Periodic Array |
1542A - Odd Set | 1567B - MEXor Mixup |
669A - Little Artem and Presents | 691B - s-palindrome |
851A - Arpa and a research in Mexican wave | 811A - Vladik and Courtesy |
1006B - Polycarp's Practice | 1422A - Fence |
21D - Traveling Graph | 1559B - Mocha and Red and Blue |
1579C - Ticks | 268B - Buttons |
898A - Rounding | 1372B - Omkar and Last Class of Math |