#include <bits/stdc++.h>
using namespace std;

const int N = 100010;

struct ScanLine {
    double y1, y2, x;
    int mark;
    bool operator<(const ScanLine &t) const {
        return x < t.x;
    }
} line[N << 1];

struct Node {
    int l, r;
    int cnt;
    double len;
} tr[N << 2];

double b[N << 2]; // 离散化数组

void pushup(int u) {
    if (tr[u].cnt)
        tr[u].len = b[tr[u].r + 1] - b[tr[u].l];
    else
        tr[u].len = tr[u << 1].len + tr[u << 1 | 1].len;
}

void build(int u, int l, int r) {
    tr[u].l = l, tr[u].r = r;
    if (l == r) return;
    int mid = (l + r) >> 1;
    build(u << 1, l, mid);
    build(u << 1 | 1, mid + 1, r);
}

void modify(int u, int l, int r, int v) {
    if (l <= tr[u].l && r >= tr[u].r) {
        tr[u].cnt += v;
        pushup(u);
        return;
    }
    int mid = (tr[u].l + tr[u].r) >> 1;
    if (l <= mid) modify(u << 1, l, r, v);
    if (r > mid) modify(u << 1 | 1, l, r, v);
    // 更新统计信息
    pushup(u);
}

int main() {
#ifndef ONLINE_JUDGE
    freopen("247.in", "r", stdin);
#endif
    ios::sync_with_stdio(false), cin.tie(0);

    int n, T = 1;
    while (cin >> n, n) {
        // 多组测试数据，记得清空
        memset(tr, 0, sizeof tr);
        memset(b, 0, sizeof b);

        for (int i = 1; i <= n; i++) {
            double x1, y1, x2, y2;
            cin >> x1 >> y1 >> x2 >> y2;
            b[2 * i - 1] = y1;
            b[2 * i] = y2;
            line[2 * i - 1] = {y1, y2, x1, 1};
            line[2 * i] = {y1, y2, x2, -1};
        }
        n *= 2;
        sort(line + 1, line + 1 + n);

        sort(b + 1, b + 1 + n);
        int tot = unique(b + 1, b + 1 + n) - b - 1;

        build(1, 1, tot - 1);

        double res = 0;
        for (int i = 1; i < n; i++) {
            int L = lower_bound(b + 1, b + 1 + tot, line[i].y1) - b;
            int R = lower_bound(b + 1, b + 1 + tot, line[i].y2) - b;
            modify(1, L, R - 1, line[i].mark);
            res += tr[1].len * (line[i + 1].x - line[i].x);
        }
        printf("Test case #%d\n", T++);
        printf("Total explored area: %.2lf\n\n", res);
    }
    return 0;
}