For problem statement at 1000-1999/1500-1599/1540-1549/1547/problemG.txt this is a correct solution, but verifier at 1000-1999/1500-1599/1540-1549/1547/verifierG.go ends with All 100 tests passed can you fix the verifier? ```go
package main

import (
	"bufio"
	"os"
	"strconv"
)

func main() {
	// Increase buffer size to handle large input efficiently
	const maxCapacity = 2048 * 1024
	buf := make([]byte, maxCapacity)

	scanner := bufio.NewScanner(os.Stdin)
	scanner.Buffer(buf, maxCapacity)
	scanner.Split(bufio.ScanWords)

	writer := bufio.NewWriter(os.Stdout)
	defer writer.Flush()

	// Helper to read the next integer
	readInt := func() int {
		scanner.Scan()
		val, _ := strconv.Atoi(scanner.Text())
		return val
	}

	if !scanner.Scan() {
		return
	}
	t, _ := strconv.Atoi(scanner.Text())

	for i := 0; i < t; i++ {
		solve(readInt, writer)
	}
}

func solve(readInt func() int, writer *bufio.Writer) {
	n := readInt()
	m := readInt()

	// Build adjacency list
	adj := make([][]int, n)
	hasSelfLoop := make([]bool, n)

	for i := 0; i < m; i++ {
		u := readInt() - 1
		v := readInt() - 1
		adj[u] = append(adj[u], v)
		if u == v {
			hasSelfLoop[u] = true
		}
	}

	// Tarjan's algorithm to find SCCs
	ids := make([]int, n)
	low := make([]int, n)
	onStack := make([]bool, n)
	stack := make([]int, 0, n)
	for i := 0; i < n; i++ {
		ids[i] = -1
	}

	idCounter := 0
	sccCount := 0
	sccID := make([]int, n)

	var dfs func(int)
	dfs = func(at int) {
		stack = append(stack, at)
		onStack[at] = true
		ids[at] = idCounter
		low[at] = idCounter
		idCounter++

		for _, to := range adj[at] {
			if ids[to] == -1 {
				dfs(to)
				if low[to] < low[at] {
					low[at] = low[to]
				}
			} else if onStack[to] {
				if ids[to] < low[at] {
					low[at] = ids[to]
				}
			}
		}

		if ids[at] == low[at] {
			for {
				node := stack[len(stack)-1]
				stack = stack[:len(stack)-1]
				onStack[node] = false
				sccID[node] = sccCount
				if node == at {
					break
				}
			}
			sccCount++
		}
	}

	for i := 0; i < n; i++ {
		if ids[i] == -1 {
			dfs(i)
		}
	}

	// Group vertices by SCC and identify internal loops
	nodesInSCC := make([][]int, sccCount)
	sccInternalLoop := make([]bool, sccCount)

	for u := 0; u < n; u++ {
		id := sccID[u]
		nodesInSCC[id] = append(nodesInSCC[id], u)
		if hasSelfLoop[u] {
			sccInternalLoop[id] = true
		}
	}

	for id := 0; id < sccCount; id++ {
		if len(nodesInSCC[id]) > 1 {
			sccInternalLoop[id] = true
		}
	}

	// DP on SCC DAG
	// Tarjan's generates SCCs in reverse topological order (sinks first).
	// So, iterating from sccCount-1 down to 0 processes in topological order.
	dpReach := make([]bool, sccCount)
	dpInf := make([]bool, sccCount)
	dpCount := make([]int, sccCount)

	// Base case: vertex 1 (index 0)
	startID := sccID[0]
	dpReach[startID] = true
	dpCount[startID] = 1

	for i := sccCount - 1; i >= 0; i-- {
		if !dpReach[i] {
			continue
		}

		// If this SCC has internal cycle or already marked infinite
		if sccInternalLoop[i] {
			dpInf[i] = true
		}

		isInf := dpInf[i]
		count := dpCount[i]

		// Propagate to neighbors
		for _, u := range nodesInSCC[i] {
			for _, v := range adj[u] {
				target := sccID[v]
				if target == i {
					continue // Edge within the same SCC
				}

				dpReach[target] = true
				if isInf {
					dpInf[target] = true
				} else {
					if !dpInf[target] {
						dpCount[target] += count
						if dpCount[target] > 2 {
							dpCount[target] = 2
						}
					}
				}
			}
		}
	}

	// Output results
	for i := 0; i < n; i++ {
		id := sccID[i]
		if !dpReach[id] {
			writer.WriteString("0")
		} else if dpInf[id] {
			writer.WriteString("-1")
		} else {
			if dpCount[id] == 1 {
				writer.WriteString("1")
			} else {
				writer.WriteString("2")
			}
		}

		if i == n-1 {
			writer.WriteByte('\n')
		} else {
			writer.WriteByte(' ')
		}
	}
}
```