from sys import stdin
from heapq import heappush, heappop
from sys import setrecursionlimit
setrecursionlimit(10000000)

w, h, n, *indata = map(int, stdin.read().split())
offset = 0
hq = []
xylist = [(-1,-1)]
for i in range(n):
    y, x = indata[offset + 2*i],indata[offset + 2*i+1]
    heappush(hq, (y, x, i+1))
    xylist.append((x,y))

par = [i for i in range(h+1)]
rank = [0 for i in range(h+1)]

def root(x):
    if par[x] == x:
        return x
    else:
        par[x] = root(par[x])
        return par[x]

def unite(x,y):
    karix = root(x)
    kariy = root(y)
    if karix == kariy:
        return 0
    if rank[karix] < rank[kariy]:
        par[karix] = kariy
    else:
        par[kariy] = karix
        if rank[karix] == rank[kariy]:
            rank[karix] += 1

def same(x,y):
    return root(x) == root(y)

prey = -1
prex = -1
preind = -1
samexlist = [[] for j in range(h+1)]
g = [[] for i in range(n+1)]
while hq:
    y, x, ind = heappop(hq)
    if prey == y:
        if same(prex,x):
            g[preind].append(ind)
            ind2 = samexlist[x][-1]
            g[ind2].append(ind)
            g[ind].append(ind2)
            que = [(ind,0)]
            route = [ind]
            check = [False for i in range(n+1)]
            check[ind] = True
            while que:
                now, inout = que.pop()
                if now == preind:
                    route.append(now)
                    route.append(ind)
                    ans = [ind]
                    lenroute = len(route)
                    parity = 0
                    for i in range(1,lenroute):
                        if parity:
                            if xylist[ans[-1]][0] == xylist[route[i]][0]:
                                ans.pop()
                                ans.append(route[i])
                            else:
                                ans.append(route[i])
                                parity = parity ^ 1
                        else:
                            if xylist[ans[-1]][1] == xylist[route[i]][1]:
                                ans.pop()
                                ans.append(route[i])
                            else:
                                ans.append(route[i])
                                parity = parity ^ 1
                    ans.pop()
                    ansx = len(ans)
                    L=[str(i) for i in ans]
                    L=' '.join(L)
                    print(L)
                    exit()
                if inout == 0:
                    que.append((now,1))
                    route.append(now)
                    for i in g[now]:
                        if not check[i]:
                            check[i] = True
                            que.append((i,0))
                else:
                    route.pop()
        else:
            unite(prex,x)
        g[ind].append(preind)
        g[preind].append(ind)
    else:
        prey = y
    if samexlist[x]:
        ind2 = samexlist[x][-1]
        g[ind2].append(ind)
        g[ind].append(ind2)
    samexlist[x].append(ind)
    prex = x
    preind = ind

print("{}".format(-1))