Problem:
Score : 100 points

Problem Statement

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 1

100 17

Sample Output 1

83

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

Sample Input 2

48 58

Sample Output 2

0

All 48 grams of sand will be gone, resulting in 0 grams.

Sample Input 3

1000000000 1000000000

Sample Output 3

0

Solution in C++14 (GCC 5.4.1) (judge verdict: Accepted)


#include "bits/stdc++.h"

// clang-format off
template <typename T> T gcd(T a, T b) { return b == 0 ? a : gcd(b, a % b); }
template <typename T> T lcm(T a, T b) { return a * b / gcd(a, b); }
template <typename T> T clamp(T val, T min, T max) { return val < min ? min : (max < val ? max : val); }
template <typename T> size_t max_index(T begin, T end) { return distance(begin, max_element(begin, end)); }
template <typename T> size_t min_index(T begin, T end) { return distance(begin, min_element(begin, end)); }
// clang-format on

// #define int long long
#define YES "Yes"
#define NO  "No"

using namespace std;

signed main(void) {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);

  bool flag = false;
  int num = 0;

  int x, t; cin >> x >> t;
  cout << max(x - t, 0) << endl;
  
  // cout << num << endl;
  // cout << (flag ? YES : NO) << endl;
  
  return 0;
}