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#include<cstdio>
#include<cstring>
#include<algorithm>
#include<iostream>
#include<queue>
#include<map>
#include<stack>
#include<cmath>
#include<set>
#include<bitset>
#include<complex>
#include<cstdlib>
#include<assert.h>
#define inc(i,l,r) for(int i=l;i<=r;i++)
#define dec(i,l,r) for(int i=l;i>=r;i--)
#define link(x) for(edge *j=h[x];j;j=j->next)
#define mem(a) memset(a,0,sizeof(a))
#define ll long long
#define eps 1e-8
#define succ(x) (1<<x)
#define lowbit(x) (x&(-x))
#define mid (x+y>>1)
#define sqr(x) ((x)*(x))
#define NM 1100005
#define nm 400005
using namespace std;
const double pi=acos(-1);
const ll inf=998244353;
ll read(){
ll x=0,f=1;char ch=getchar();
while(!isdigit(ch)){if(ch=='-')f=-1;ch=getchar();}
while(isdigit(ch))x=x*10+ch-'0',ch=getchar();
return f*x;
}
int n,m,tot;
ll a[NM],b[NM],c[NM],ans;
char _s[NM];
void fwt(ll*a,int f=0){
for(int k=1;k<n;k<<=1)
for(int i=0;i<n;i+=k<<1)
for(int j=0;j<k;j++){
ll x=a[i+j],y=a[i+j+k];
a[i+j]=x+y;
a[i+j+k]=x-y;
}
if(f)inc(i,0,n-1)a[i]/=n;
}
int main(){
n=read();m=read();
inc(i,1,n){
scanf("%s",_s+1);
inc(j,1,m)if(_s[j]-'0')a[j]|=succ(i-1);
}
inc(i,1,m)c[a[i]]++;
tot=succ(n);
inc(i,0,tot-1)b[i]=__builtin_popcount(i),b[i]=min(b[i],n-b[i]);
n=tot;
fwt(c);fwt(b);
inc(i,0,n-1)b[i]=b[i]*c[i];
fwt(b,1);
ans=inf;
inc(i,0,n-1)ans=min(ans,b[i]);
printf("%lld\n",ans);
return 0;
}
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