#include <cstdio>
#include <cstring>
#include <algorithm>
#include <vector>
#include <queue>
#include <iostream>
using namespace std;
const int maxn = 4010;
const int INF = 1e9+10;
struct Edge{
    int to, cap, rev;
};
vector<Edge> G[maxn];
int cnt[maxn];
int level[maxn];
int s, t;
int n, m, k;
int l, r;
void add_edge(int u, int v, int cap){
    G[u].push_back(Edge{v, cap, G[v].size()});
    G[v].push_back(Edge{u, 0, G[u].size()-1});
}
void bfs(int s){
    memset(level, -1, sizeof(level));
    queue<int> q;
    q.push(s);
    level[s] = 0;
    while(!q.empty()){
        int v = q.front();
        q.pop();
        for(int i=0; i<G[v].size(); i++){
            Edge& e = G[v][i];
            if(e.cap>0&&level[e.to]<0){
                level[e.to] = level[v]+1;
                q.push(e.to);
            }
        }
    }
}
int dfs(int v, int t, int flow){
    if(v == t) return flow;
    for(int& i=cnt[v]; i<G[v].size(); i++){
        Edge& e = G[v][i];
        if(e.cap>0&&level[v]<level[e.to]){
            int d = dfs(e.to, t, min(flow, e.cap));
            if(d>0){
                e.cap -= d;
                G[e.to][e.rev].cap += d;
                return d;//一旦有一条路径满足就立即返回！
            }
        }
    }
    return 0;
}
int max_flow(int s, int t){
    int flow = 0;
    for(;;){
        //构造层次图
        bfs(s);
        //无法连通终点，结束访问
        if(level[t]<0) return flow;
        int f;
        //cnt数组记录在递归的过程中的边的顺序。
        memset(cnt, 0, sizeof(cnt));
        //当存在增广路的时候不断的进行增广
        while((f = dfs(s, t, INF))>0){
            flow+=f;
        }
    }
}
int d[maxn];
int main()
{
    int kase = 1;
    while(~scanf("%d%d%d", &n, &m, &k)){
        for(int i=0; i<maxn; i++) G[i].clear();
        memset(d, 0, sizeof(d));
        scanf("%d%d", &l, &r);
        int u, v;
        int sum = 0;
        for(int i=0; i<k; i++){
            scanf("%d %d", &u, &v);
            add_edge(u, v+n, 1);
        }
        int ss = 4002;
        int tt = 4003;
        for(int i=1; i<=n; i++) add_edge(0, i, r-l), add_edge(ss, i, l);
        for(int i=1; i<=m; i++) add_edge(i+n, 4001, r-l), add_edge(i+n, tt, l);
        add_edge(4001, 0, 1000000);
        int ans = max_flow(ss, tt);
        //cout<<ans<<endl;
        if(ans == n*l)printf("Case %d: Yes\n", kase++);
        else printf("Case %d: No\n", kase++);
    }
    return 0;
}