#include <stdio.h>
long long n,m,i,j,x,y,a,t;int main(){for(scanf("%d%d",&n,&m);i<n;++i){for(a=j=0;j<m;++j)scanf("%lld",&t),a+=t;a-=y-x;a<0?x-=a:y+=a;}printf("%lld\n",x>y?x:y);}