#include <cstdio>
#include <iostream>
using namespace std;
const int maxn = 100000 + 10;
int n, a[maxn], b[maxn];
int main()
{
int T, flag = 0, i, j, sum; scanf("%d", &T);
while (T--) {
scanf("%d", &n);
for (int i = 0; i < n; i++) scanf("%d", &a[i]);
for (int i = 0; i < n; i++) scanf("%d", &b[i]);
printf("Case %d: ", ++flag);
bool ok = false;
for (i = 0; i < n; i++) {
j = i, sum = 0;
while (true) {
sum += a[j] - b[j];
if (sum < 0) {
j = (j + 1) % n;
break;
}
else j = (j + 1) % n;
if (j == i) {
ok = true;
break;
}
}
if (ok) break;
else {
if (j > i) i = j - 1;//-1是为了抵消i++
else break;
}
}
if (ok) printf("Possible from station %d\n", i + 1);
else printf("Not possible\n");
}
return 0;
}
