#include<stdio.h>#include<string.h>#define INF 0x7FFFFFFF#define MAXD 10010#define MAXM 10000010int first[MAXD], next[MAXM], u[MAXM], v[MAXM], N, M, e;long long int cap[MAXM], flow[MAXM];int S, T, work[MAXD], d[MAXD], q[MAXD], s[MAXD];void add(int a, int b, int w){    u[e] = a;    v[e] = b;    cap[e] = flow[e] = w;    next[e] = first[a];    first[a] = e;    e ++;}int init(){int i, minx, maxx, x, y, a, b, w;if(scanf("%d", &N) != 1)return 0;    minx = INF;    maxx = 0;for(i = 1; i <= N; i ++)        scanf("%d%d", &x, &y);    S = 1;    T = N;    scanf("%d", &M);    memset(first, -1, sizeof(first));    e = 0;for(i = 0; i < M; i ++)    {        scanf("%d%d%d", &a, &b, &w);        add(a, b, w);        add(b, a, w);    }return 1;}int bfs(){int i, j, rear;    memset(d, -1, sizeof(d));    rear = 0;    d[S] = 0;    q[rear ++] = S;for(i = 0; i < rear; i ++)for(j = first[q[i]]; j != -1; j = next[j])if(flow[j] && d[v[j]] == -1)            {                d[v[j]] = d[q[i]] + 1;if(v[j] == T)return 1;                q[rear ++] = v[j];            }return 0;}int dinic(){int cur, res = 0, r;while(bfs())    {        memcpy(work, first, sizeof(first));        r = 0;        cur = S;for(;;)        {if(cur == T)            {int minr = 0, a = INF;for(int i = 0; i < r; i ++)if(flow[s[i]] < a)                    {                        a = flow[s[i]];                        minr = i;                    }for(int i = 0; i < r; i ++)                {                    flow[s[i]] -= a;                    flow[s[i] ^ 1] += a;                }                r = minr;                cur = u[s[r]];                res += a;            }int i;for(i = work[cur]; i != -1; i = next[i])            {if(flow[i] == 0)continue;if(d[cur] + 1 == d[v[i]])break;            }            work[cur] = i;if(i != -1)            {                s[r ++] = i;                cur = v[i];            }else            {                d[cur] = -1;if(r == 0)break;                r --;                cur = u[s[r]];            }        }    }return res;}void printresult(){int i;for(i = 0; i < 2 * M; i += 2)    {if(flow[i] > cap[i])            printf("%d %d %I64d\n", u[i ^ 1], v[i ^ 1], cap[i ^ 1] - flow[i ^ 1]);else            printf("%d %d %I64d\n", u[i], v[i], cap[i] - flow[i]);    }}int main(){while(init())    {long long int res = dinic();        printf("%I64d\n", res);        printresult();    }return 0;}