package main

import (
	"bufio"
	"fmt"
	"os"
)

func main() {
	reader := bufio.NewReader(os.Stdin)
	var n int
	fmt.Fscan(reader, &n)

	L := -1000000000
	U := 1000000000
	pref := 0

	for i := 0; i < n; i++ {
		var c, d int
		fmt.Fscan(reader, &c, &d)

		if d == 1 {
			if 1900-pref > L {
				L = 1900 - pref
			}
		} else {
			if 1899-pref < U {
				U = 1899 - pref
			}
		}
		pref += c
	}

	if L > U {
		fmt.Println("Impossible")
	} else if U == 1000000000 {
		fmt.Println("Infinity")
	} else {
		fmt.Println(U + pref)
	}
}