#include<iostream>#include<cstdio>#include<string>#include<cstring>#include<algorithm>#define ll intusing namespace std;const int maxn = 1000005;ll read(){    ll x=0,f=1;char ch=getchar();    while(ch<‘0‘||ch>‘9‘){if(ch==‘-‘)f=-1;ch=getchar();}    while(ch>=‘0‘&&ch<=‘9‘){x=x*10+ch-‘0‘;ch=getchar();}    return x*f;}int v[maxn],sum;int n,m,a,b,c;int main(){    freopen("debt.in","r",stdin);    freopen("debt.out","w",stdout);    n = read();    m = read();    for(int i = 1;i <= m;i++){        a = read();        b = read();        c = read();        v[a] -= c;        v[b] += c;    }    for(int i = 1;i <= n;i++){        if(v[i] >= 0) sum += v[i];        else sum -= v[i];    }    sum >>= 1;    cout<<sum;    return 0;}