n,q = map(int,input().split())

tree = [[]for _ in range(n)]
query = [0]*n

for _ in range(n-1):
    a,b = map(int,input().split())
    tree[a-1].append(b-1)
    tree[b-1].append(a-1)

visited = [False]*n

def visit(s):
    visited[s] = True
    ret = 1
    for w in tree[s]:
        if not visited[w]:
            ret += visit(w)
    query[s] = ret
    return ret

visit(0)
ans = 0
for _ in range(q):
    p,x = map(int,input().split())
    ans += x * query[p-1]
    print(ans)