#include<iostream>
#include<cstdio>
#include<algorithm>
using namespace std;
long long n,m,br,a,b,start[1001],end[1001],ans,max1;
int main()
{
    freopen("bdz.in","r",stdin);
    freopen("bdz.out","w",stdout);
	scanf("%lld%lld",&n,&m);
	for(int i=1; i<=m; i++)
	{
	    scanf("%lld%lld%lld",&br,&a,&b);
	    start[a]+=br; end[b]+=br;
	}
	for(int i=1; i<=n; i++)
	{
	    ans+=start[i]-end[i];
	    if(ans%64==0) {max1=max(max1,ans/64);}
	    else max1=max(max1,ans/64+1);
	}
	printf("%lld\n",max1);
	return 0;
}