def get_children(graph,v):
    return {i for i in range(len(graph[v])) if graph[v][i] == 1}

def dfs(graph ,v, visited = set()):
    visited.add(v)
    for u in get_children(graph,v) - visited:
        dfs(graph,u,visited)
    return visited
n,k = map(int, input().split())
g1 = [[0] * n for i in range(n)]
g2 = [[0] * n for i in range(n)]


for i in range(k):
    oper, a,b  = input().split()
    a = int(a) -1
    b = int(b) - 1
    if oper == '+':
        g1[a][b] = 1
        g1[b][a] = 1
        g2[a][b] = 1
        g2[b][a] = 1
    elif oper == '-':
        g1[a][b] = 1
        g1[b][a] = 1
        g2[a][b] = 0
        g2[b][a] = 0
    else:
        dfs1 = dfs(g1,a)
        dfs2 = dfs(g2,a)
        if a in dfs1 and b in dfs1:
            if a in dfs2 and b in dfs2:
                print('-')
            else:
                print('+')
        else:
            print('?')