import sys

input = sys.stdin.readline

N,M = map(int,input().split())
edge = [tuple(map(int,input().split())) for i in range(M)]

cost = [[10**18 for j in range(N)] for i in range(N)]
for i in range(N):
    cost[i][i] = 0
for u,v,c in edge:
    for i in range(u):
        for j in range(v-1,N):
            cost[i][j] = min(cost[i][j],cost[i][u-1] + cost[v-1][j] + 1)

edge.sort(key=lambda x:x[2])
ans = [[-1 for i in range(N)] for j in range(N)]
for u,v,c in edge:
    for i in range(u):
        for j in range(v-1,N):
            cost[i][j] = min(cost[i][j],cost[i][u-1] + cost[v-1][j] - 1)
            if cost[i][j] <=0 and ans[i][j]==-1:
                ans[i][j] = c

Q = int(input())
res = [-1 for i in range(Q)]
for i in range(Q):
    s,t = map(int,input().split())
    res[i] = ans[s-1][t-1]

print(*res,sep="\n")