from collections import deque

def shortest_hops(adj, start, target):
    dist = [-1] * len(adj)
    dist[start] = 0
    queue = deque([start])
    while queue:
        u = queue.popleft()
        if u == target:
            return dist[u]
        for v in adj[u]:
            if dist[v] == -1:
                dist[v] = dist[u] + 1
                queue.append(v)
    return -1