def LowLink(n, edges): ord = [-1] * n low = [-1] * n isartic = [False] * n bridge = [] k = 0 def dfs(root, k): stack = [(~root, -1), (root, -1)] cnt = 0 while stack: pos, bpos = stack.pop() if pos >= 0: if bpos != -1 and ord[pos] != -1: low[bpos] = min(low[bpos], ord[pos]) stack.pop() continue low[pos] = k ord[pos] = k k += 1 for npos in edges[pos]: if npos == bpos: continue if ord[npos] == -1: if bpos == -1: cnt += 1 stack.append((~npos, pos)) stack.append((npos, pos)) else: low[pos] = min(low[pos], ord[npos]) if npos == root: cnt -= 1 else: pos = ~pos if ord[bpos] < low[pos]: if bpos != -1: bridge.append((min(bpos, pos), max(bpos, pos))) if low[pos] >= ord[bpos] and bpos != root and bpos != -1: isartic[bpos] = True if bpos != -1: low[bpos] = min(low[bpos], low[pos]) if cnt >= 2: isartic[root] = True return k for i in range(n): if ord[i] == -1: k = dfs(i, k) return isartic, bridge class UnionFind: def __init__(self, n): self.n = n self.parents = [-1] * n self.group = 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 self.group -= 1 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 self.group def all_group_members(self): dic = {r:[] for r in self.roots()} for i in range(self.n): dic[self.find(i)].append(i) return dic def __str__(self): return '\n'.join('{}: {}'.format(r, self.members(r)) for r in self.roots()) n, m, Q = map(int, input().split()) edges = [[] for _ in range(n)] for _ in range(m): u, v = map(int, input().split()) u -= 1 v -= 1 edges[u].append(v) edges[v].append(u) _, bridge = LowLink(n, edges) UF = UnionFind(n) for u, v in bridge: UF.union(u, v) for _ in range(Q): x, y = map(int, input().split()) if UF.same(x - 1, y - 1): print("Yes") else: print("No")