from collections import defaultdict,deque class UnionFind(): def __init__(self, n): self.n = n self.parents = [-1] * n def find(self, x): if self.parents[x] < 0: return x else: self.parents[x] = self.find(self.parents[x]) return self.parents[x] def union(self, x, y): x = self.find(x) y = self.find(y) if x == y: return if self.parents[x] > self.parents[y]: x, y = y, x self.parents[x] += self.parents[y] self.parents[y] = x def size(self, x): return -self.parents[self.find(x)] def same(self, x, y): return self.find(x) == self.find(y) def members(self, x): root = self.find(x) return [i for i in range(self.n) if self.find(i) == root] def roots(self): return [i for i, x in enumerate(self.parents) if x < 0] def group_count(self): return len(self.roots()) def all_group_members(self): group_members = defaultdict(list) for member in range(self.n): group_members[self.find(member)].append(member) return group_members def __str__(self): return '\n'.join(f'{r}: {m}' for r, m in self.all_group_members().items()) def scc_decomposition(G): n = len(G) G_rev = [[] for _ in range(n)] for u in range(n): for v in G[u]: G_rev[v].append(u) # dfs vs = [] visited = [False] * n used = [False] * n for u in range(n): if visited[u]: continue stack = [u] while stack: v = stack.pop() if used[v]: continue if not visited[v]: visited[v] = True else: vs.append(v) used[v] = True continue stack.append(v) for c in G[v]: if not visited[c]: stack.append(c) # reverse dfs visited = [False] * n component = [-1] * n k = 0 for u in vs[::-1]: if visited[u]: continue stack = [u] while stack: v = stack.pop() visited[v] = True component[v] = k for c in G_rev[v]: if not visited[c]: stack.append(c) k += 1 return component # 強連結成分分解(SCC): グラフGに対するSCCを行う # 入力: : 頂点サイズ, : 順方向の有向グラフ, : 逆方向の有向グラフ # 出力: (<ラベル数>, <各頂点のラベル番号>) def scc(N, G, RG): order = [] used = [0]*N group = [None]*N def dfs(s): used[s] = 1 for t in G[s]: if not used[t]: dfs(t) order.append(s) def rdfs(s, col): group[s] = col used[s] = 1 for t in RG[s]: if not used[t]: rdfs(t, col) for i in range(N): if not used[i]: dfs(i) used = [0]*N label = 0 for s in reversed(order): if not used[s]: rdfs(s, label) label += 1 return label, group N,M,Q = map(int,input().split()) G0 = [[] for _ in range(N)] for _ in range(M): u,v = map(lambda x:int(x)-1,input().split()) G0[u].append(v) G0[v].append(u) query = [] for _ in range(Q): x,y = map(lambda x:int(x)-1,input().split()) query.append((x,y)) cmp = scc_decomposition(G0) cmpmemo = defaultdict(list) for i in range(N): cmpmemo[cmp[i]].append(i) G = [[] for _ in range(N)] RG = [[] for _ in range(N)] seen = [0] * N for key in cmpmemo.keys(): st = cmpmemo[key][0] q = deque() q.append((st,-1)) while q: now,back = q.popleft() if back != -1: G[back].append(now) RG[now].append(back) if seen[now]: continue seen[now] += 1 for nx in G0[now]: if nx == back: continue if seen[nx] <= 1: q.appendleft((nx,now)) cmp = scc_decomposition(G) cnt = defaultdict(int) for i in range(N): cnt[cmp[i]] += 1 uf = UnionFind(N) G0set = [set() for _ in range(N)] for u in range(N): for v in G0[u]: G0set[u].add(v) if cmp[u] == cmp[v]: continue uf.union(u,v) for x,y in query: if uf.same(x,y): print('Yes') else: print('No')