N,Q = list(map(int,input().split()))
a = [0] * (N-1)
b = [0] * (N-1)
for i in range(N - 1):
    a[i],b[i] = list(map(int,input().split()))
p = [0] * Q
x = [0] * Q
for i in range(Q):
    p[i],x[i] = list(map(int,input().split()))
tree = [[] for _ in range(N+1)]
for i in range(N-1):
    tree[a[i]].append(b[i])
    tree[b[i]].append(a[i])
sub = [1] * (N+1)
"""
def tansaku(now = 1,parent = 0):
    if len(tree[now]) == 1:
        return 1
    else:
        for i in tree[now]:
            if i != parent:
                sub[now] += tansaku(i,now)
        return sub[now]
tansaku()
"""
#再帰1000回しかしてくれない
q = []
flags = [False] * (N+1)
q.append((1,0))
while len(q):
    now,parent = q.pop()
    if flags[now]:
        for i in tree[now]:
            if i != parent:
                sub[now] += sub[i]
    else:
        flags[now] = True
        q.append((now,parent))
        for i in tree[now]:
            if i != parent:
                q.append((i,now))
    
_sum = 0
for i in range(Q):
    _sum += sub[p[i]] * x[i]
    print(_sum)