We have a sandglass that runs for X seconds. The sand drops from the upper bulb at a rate of 1 gram per second. That is, the upper bulb initially contains X grams of sand.
How many grams of sand will the upper bulb contains after t seconds?

-----Constraints-----
 - 1≤X≤10^9
 - 1≤t≤10^9
 - X and t are integers.

-----Input-----
The input is given from Standard Input in the following format:
X t

-----Output-----
Print the number of sand in the upper bulb after t second.

-----Sample Input-----
100 17

-----Sample Output-----
83

17 out of the initial 100 grams of sand will be consumed, resulting in 83 grams.

Difficulty: introductory

Starter code:

Solutions:
x, t = list(map(int, input().split()))
print((max(0, x - t)))


a,b=list(map(int,input().split()))
if a <= b:
  print((0))
else:
  print((a-b))


from collections import Counter,defaultdict,deque
from heapq import heappop,heappush,heapify
import sys,bisect,math,itertools,fractions
sys.setrecursionlimit(10**8)
mod = 10**9+7
INF = float('inf')
def inp(): return int(sys.stdin.readline())
def inpl(): return list(map(int, sys.stdin.readline().split()))

x,t = inpl()
print(max(x-t,0))

X,t = list(map(int,input().split()))

if X > t:
    print((X-t))
else:
    print((0))


#   AtCoder abc072 a
#   ストレッチ課題

#   入力
x, t = list(map(int, input().split()))

#   処理
if (x -t) <= 0:
    print((0))
else:
    print((x - t))


x, t = map(int, input().split())

if x <= t:
    print(0)
else:
    print(x -t)

X, t = map(int, input().split())
print(max(X-t, 0))

# 072_a
X,t=map(int,input().split())
if (1<=X and X<=10**9) and (1<=t and t<=10**9):
    if X<=t:
        print(0)
    else:
        print(X-t)

# 入力
X, t = map(int, input().split())

# Xがtより小さいなら0、そうじゃないならX-tの結果を出力
if X < t:
    print(0)
else:
    print(X - t)

x,t = list(map(int,input().split()))
print((max(x-t,0)))


x, t = map(int, input().split())
print(x-t if x>=t else 0)

x, t= map(int, input().split())
print(max(x-t, 0))

#
# abc072 a
#
import sys
from io import StringIO
import unittest


class TestClass(unittest.TestCase):
    def assertIO(self, input, output):
        stdout, stdin = sys.stdout, sys.stdin
        sys.stdout, sys.stdin = StringIO(), StringIO(input)
        resolve()
        sys.stdout.seek(0)
        out = sys.stdout.read()[:-1]
        sys.stdout, sys.stdin = stdout, stdin
        self.assertEqual(out, output)

    def test_入力例_1(self):
        input = """100 17"""
        output = """83"""
        self.assertIO(input, output)

    def test_入力例_2(self):
        input = """48 58"""
        output = """0"""
        self.assertIO(input, output)

    def test_入力例_3(self):
        input = """1000000000 1000000000"""
        output = """0"""
        self.assertIO(input, output)


def resolve():
    X, t = list(map(int, input().split()))
    print((max(X-t, 0)))


def __starting_point():
    # unittest.main()
    resolve()

__starting_point()

X, t = map(int, input().split())
print(X-t if t<X else 0)

X,t=list(map(int,input().split()))
print((max(0,X-t)))


def LI():
    return list(map(int, input().split()))


X, t = LI()
ans = max(X-t, 0)
print(ans)


import sys

sys.setrecursionlimit(10 ** 7)
input = sys.stdin.readline
f_inf = float('inf')
mod = 10 ** 9 + 7


def resolve():
    x, t = list(map(int, input().split()))
    print((max(0, x - t)))


def __starting_point():
    resolve()

__starting_point()

x,t=map(int,input().split())
print(max(0,x-t))

x,t=map(int,input().split())

print(max((x-t),0))

x, t = list(map(int, input().split()))

def answer(x: int, t: int) -> int:
    if x > t:
        return x - t
    else:
        return 0

print(answer(x, t))

def iroha():
    x,t = list(map(int, input().split()))
    print((0 if t >= x else x-t))

def __starting_point():
    iroha()


__starting_point()

def main():
    X,t = list(map(int,input().split()))
    tmp = X-t
    if tmp<0:
        return 0
    else:
        return tmp

print((main()))


X, t = list(map(int, input().split()))

if X - t >= 0:
    print((X - t))
else:
    print('0')


a,b = map(int,input().split())
if a - b > 0:
    print(a - b)
else:
    print(0)

x,t=map(int,input().split())

if x<=t:
    print(0)
else:
    print(x-t)

x,t=map(int,input().split())
if x-t>0:
    print(x-t)
else:
    print(0)

X, t = list(map(int, input().split()))
print((max(X - t, 0)))


x, t = map(int, input().split())
print(max(0, x - t))

x,t = list(map(int,input().split()))
print(( x-t if x-t > 0 else 0))


X, t = map(int, input().split())
print(X - t if X - t >= 0 else 0)

X, t = map(int, input().split())
if X < t:
    print(0)
else:
    print(X - t)

# 入力
X, t = map(int, input().split())

# 出力
if X <= t:
    print(0)
else:
    print(X - t)

x,t=map(int,input().split())
print(x-t if x>=t else 0)

a,b=map(int,input().split())
if a-b>0:
  print(a-b)
else:
  print(0)

X, t = map(int,input().split())
answer = int( X - t )
if answer > 0:
    print(answer)
else:
    print(0)

X,t = map(int,input().split())
ans = X-min(X,t)
print(ans)

import sys

X, t = map(int, sys.stdin.readline().split())
print(max(0, X - t))

x,t=map(int,input().split())
if x>=t:
  print(x-t)
else:
  print(0)

x, t = map(int, input().split())
print(max(0, x - t))

a,b=map(int,input().split())
print(max(0,a-b))

X, t = list(map(int, input().split()))
print((max(X-t,0)))


x,t = map(int,input().split())
print(x-t if x>t else 0)

a, b = map(int, input().split())

if a > b:
    print(a - b)
else:
    print(0)

a,b=map(int,input().split())
 
c=a-b

if c<0:
  print(0)
else:
  print(c)

x,t=map(int,input().split())
if x<t:
    print(0)
else:
    print(x-t)

x, t = list(map(int, input().split()))
if x - t >= 0:
    print((x - t))
else:
    print((0))


X, t = map(int, input().split())
print(max(X-t,0))

n = [int(x) for x in input().split()]
print(max(0,n[0]-n[1]))

X, t=map(int, input().split(" "))

print(max(X-t, 0))


x,t = map(int,input().split())
if x-t <= 0:
    print('0')
else:
    print(x-t)

a,b = map(int,input().split())
print(max(a-b,0))

x, t = map(int, input().split())

print(max(x - t, 0))

x,t=map(int,input().split())
print(x-t) if x-t>=0 else print(0)

# 入力
X, t = map(int,input().split())
# 処理
answer = X - t
if X <= t:
    print(0)
else:
    print(answer)

X, t = map(int, input().split())

print(max(X-t, 0))

X, x = list(map(int, input().split()))

if X - x < 0:
    print((0))
else:
    print((X - x))


A,B=list(map(int,input().split()))
print(A-B if A-B>0 else 0)

x, t = map(int, input().split())
print(x - t if x >= t else 0)

# A - Sandglass2

# X秒測れる砂時計で、t秒後に残っている砂は何グラムか


X,t = list(map(int,input().split()))

if X <= t:
    print('0')
else:
    print((X - t))


X, t = map(int, input().split())

print(X - t if X - t >= 0 else 0)

a,b = map(int,input().split())

print(0 if a-b <= 0 else a-b)

a, b = map(int, input().split())
c = a - b
if c < 0:
    print(0)
else:
    print(c)

X, t = map(int, input().split())

if X <= t:
    print(0)
else:
    print(X - t)

X, t = map(int, input().split())
print(max(X-t, 0))

lst = input().split()

d = int(lst[0]) - int(lst[1])

if 0 <= d:
   print(d)
else:
   print(0)

# 問題文
# X秒を測れる砂時計があります。
# はじめ上のパーツに砂が X[g] あり、1秒間に 1[g] 砂が落ちます。
# なお、上のパーツにもう砂が残っていない場合は砂は落ちません。
# t秒後に上のパーツに残っている砂は何gでしょう。

# x（秒）、t（秒後）：標準入力（数値）
x,t = map(int, input().split())

# x>tの時、砂が残っている x-tが存在する
# x<=tの時、砂は残っておらず砂は落ちない
weight = 0
if x > t:
    weight = x - t
else:
    weight = 0

print(weight)

a,b = map(int,input().split())
print((a-b,0)[a<b])

X,t = map(int,input().split())
print(max(X-t,0))

x, t = map(int, input().split())


print(max(x-t,0))

X, t = map(int, input().split())
x = X - t
 
if x > 0:
    print(x)
else:
    print(0)

x,t = map(int,input().split())
print(max(x-t,0))

X, t = map(int,input().split())

if t >= X:
    print("0")
else:
    print(X - t)

a,b = map(int,input().split())

if a < b:
    print(0)
else:
    print(a-b)

X, t = map(int, input().split())

if X >= t:
    print(X - t)
else:
    print(0)

X, t = map(int, input().split())

if X - t <= 0:
    print(0)
else:
    print(X - t)

X,t=map(int,input().split())
if X-t<0 :
  print(0)
else :
  print(X-t)

x, t = map(int , input().split())
if t >= x:
  print(0)
else:
  print(x-t)

# X秒を測れる砂時計があります。
# はじめ上のパーツに砂が X[g] あり、1秒間に 1[g] 砂が落ちます。
# なお、上のパーツにもう砂が残っていない場合は砂は落ちません。
# t秒後に上のパーツに残っている砂は何gでしょう。

# 制約
# 1 ≦ X ≦ 1000000000
# 1 ≦ t ≦ 1000000000
# X, t は整数

# 標準入力から X, tの値を取得する
x, t = list(map(int, input().split()))

# t秒後の砂の[g]グラム数を計算し、出力する
result = 0

if x > t:   # xがtより大きい場合は、残りx - t[g]
    result = x - t
else:
    result = 0  # tの方が大きい場合は残り 0[g]

print(result)


X,t = map(int,input().split())

if X - t > 0:
    print(X - t)

else:
    print('0')

x,t = map(int, input().split())
print(x-t if x-t >= 0 else 0)

x, t = map(int, input().split())

answer = x - t

if answer <= -1:
    print(0)
else:
    print(answer)

#from statistics import median
#import collections
#aa = collections.Counter(a) # list to list || .most_common(2)で最大の2個とりだせるお a[0][0]
from math import gcd
from itertools import combinations,permutations,accumulate, product # (string,3) 3回
#from collections import deque
from collections import deque,defaultdict,Counter
import decimal
import re
import math
import bisect
import heapq
#
#
#
# pythonで無理なときは、pypyでやると正解するかも！！
#
#
# my_round_int = lambda x:np.round((x*2 + 1)//2)
# 四捨五入g
#
# インデックス系
# int min_y = max(0, i - 2), max_y = min(h - 1, i + 2);
# int min_x = max(0, j - 2), max_x = min(w - 1, j + 2);
#
#
import sys
sys.setrecursionlimit(10000000)
mod = 10**9 + 7
# mod = 9982443453
# mod = 998244353
INF = float('inf')
from sys import stdin
readline = stdin.readline
def readInts():
  return list(map(int,readline().split()))
def readTuples():
    return tuple(map(int,readline().split()))
def I():
    return int(readline())
X,t = readInts()
print((0 if X <= t else X-t))


s,t = map(int,input().split())
ans = s-t
if ans < 0:
  print(0)
else:
  print(ans)

# A - Sandglass2
# https://atcoder.jp/contests/abc072/tasks/abc072_a

X, t = list(map(int, input().split()))

result = X - t

if result < 0:
    result = 0

print(result)


x, t = map(int, input().split())
if x > t:
  print(x - t)
else:
  print(0)

x, t = list(map(int, input().split()))
print((0 if x <= t else x - t))


X, t = list(map(int, input().split()))
print((max(0, X - t)))


X, t = map(int, input().split())

print(X - t if X > t else 0)

x,t=map(int, input().split())     
print(x-t if x-t>=0 else 0)

x,t = map(int, input().split())
if x > t:
    print(x- t)
else:
    print(0)

x,t=map(int,input().split())
print(max(0,x-t))

a, b = map(int, input().split())
x = a -b
if x >= 0:
  print(x)
else:
  print(0)

x, t = map(int, input().split())
f = lambda x: x if x > 0 else 0
print(f(x-t))

x,t = map(int,input().split())

print(x-t) if x > t else print(0)


# Xgある砂が1秒に1g落ちる砂時計 t秒後に何g残るか

X, t = map(int, input().split())
x = X - t

if x > 0:
    print(x)
else:
    print(0)

x,t = map(int, input().split())
print(max(x-t,0))

#
x,t=map(int,input().split())
if x-t>0:
    print(x-t)
else:
    print(0)