ural 1701

#include <cstdio>
#include <cstring>
#include <algorithm>

using namespace std;
const int maxn = 100007;
const int INF = 1000 * 1000 * 1000;
int fa[maxn], val[maxn], max_wage[maxn], mx[maxn];
int ans[maxn];
int n, m, flag;

int findFa(int x) {
if (x == fa[x]) {
return x;
}
int cnt_fa = fa[x];
fa[x] = findFa(fa[x]);
val[x] += val[cnt_fa];
return fa[x];
}

int unionSet(int a, int b, int c) {
int x = findFa(a);
int y = findFa(b);
if (x == y) {
return 1;
}
if (b == 0) {
ans[x] = c + val[a];
ans[y] = val[b];
ans[a] = c;
}
if (val[a] + c > val[b]) {
fa[y] = x;
int temp = val[a] + c - val[b];
mx[x] = max(mx[x], mx[y] + temp);
if (mx[x] > INF) {
flag = 1;
}
val[y] = temp;
if (ans[y] != -1) {
ans[x] = ans[y] + val[y];
}
if (ans[x] != -1) {
if (mx[x] > ans[x]) {
flag = 1;
}
}
}
else {
fa[x] = y;
int temp = val[b] - c - val[a];
mx[y] = max(mx[y], mx[x] + temp);
if (mx[y] > INF) {
flag = 1;
}
val[x] = temp;
if (ans[x] != -1) {
ans[y] = ans[x] + val[x];
}
if (ans[y] != -1) {
if (mx[y] > ans[y]) {
flag = 1;
}
}
}
return 0;
}
int main() {
//    freopen("in.txt", "r", stdin);
scanf("%d%d", &n, &m);
int i;
flag = 0;
memset(val, 0, sizeof(val));
memset(ans, -1, sizeof(ans));
memset(mx, 0, sizeof(mx));
for (int i = 0; i < n; i++) {
fa[i] = i;
}
ans[0] = 0;
for (i = 1; i <= m; i++) {
int a, b, c;
scanf("%d%d%d", &a, &b, &c);
if (c < 0) {
c = -c;
swap(a, b);
}
if (a == 0 && c > 0) {
flag = 1;
break;
}
if (unionSet(a, b, c) && val[a] + c != val[b]) {
flag = 1;
break;
}
if (flag) {
break;
}
}
if (flag) {
printf("Impossible after %d statements\n", i);
return 0;
}
for (int i = 0; i < n; i++) {
findFa(i);
}
int f0 = findFa(0);
ans[0] = 0;
ans[f0] = val[0];
for (int i = 1; i < n; i++) {
int cnt_fa = findFa(i);
if (cnt_fa != f0 && cnt_fa == i) {
ans[i] = INF;
}
if (cnt_fa == f0 && cnt_fa != i) {
ans[i] = ans[f0] - val[i];
}
}
for (int i = 1; i < n; i++) {
int cnt_fa = findFa(i);
if (ans[cnt_fa] == INF) {
ans[i] = ans[cnt_fa] - val[i];
}
}
printf("Possible\n");
for (int i = 0; i < n; i++) {
printf("%d\n", ans[i]);
}
return 0;
}