import sys
from collections import deque

def main():
    n, q = map(int, sys.stdin.readline().split())
    adj = [[] for _ in range(n+1)]
    for _ in range(n-1):
        a, b = map(int, sys.stdin.readline().split())
        adj[a].append(b)
        adj[b].append(a)
    
    # BFS to build parent and children structure
    parent = [0] * (n+1)
    children = [[] for _ in range(n+1)]
    visited = [False] * (n+1)
    queue = deque([1])
    visited[1] = True
    parent[1] = -1  # mark root's parent
    
    while queue:
        u = queue.popleft()
        for v in adj[u]:
            if not visited[v]:
                visited[v] = True
                parent[v] = u
                children[u].append(v)
                queue.append(v)
    
    # Calculate subtree sizes using iterative post-order traversal
    subtree_size = [1] * (n+1)
    stack = [(1, False)]
    
    while stack:
        node, visited_flag = stack.pop()
        if not visited_flag:
            stack.append((node, True))
            # Add children in reverse to process them in order
            for child in reversed(children[node]):
                stack.append((child, False))
        else:
            for child in children[node]:
                subtree_size[node] += subtree_size[child]
    
    # Process each query and print the sum
    total = 0
    for _ in range(q):
        p, x = map(int, sys.stdin.readline().split())
        total += subtree_size[p] * x
        print(total)

if __name__ == "__main__":
    main()