func_code_string: #include <bits/stdc++.h>   using namespace std;   template <class T>   inline void remax(T& A, T B) {     if (A < B) A = B;   }   template <class T>   inline void remin(T& A, T B) {     if (A > B) A = B;   }   string ToString(long long num) {     string ret;     do {       ret += ((num % 10) +  0 );       num /= 10;     } while (num);     reverse(ret.begin(), ret.end());     return ret;   }   long long ToNumber(string s) {     long long r = 0, p = 1;     for (int i = s.size() - 1; i >= 0; --i) r += (s[i] -  0 ) * p, p *= 10;     return r;   }   long long Gcd(long long a, long long b) {     while (a %= b ^= a ^= b ^= a)       ;     return b;   }   long long Power(long long base, long long power) {     long long ret = 1;     while (power) {       if (power & 1) ret *= base;       power >>= 1;       base *= base;     }     return ret;   }   long long PowerMod(long long base, long long power, long long mod) {     if (!power) return 1;     if (power & 1) return (base * PowerMod(base, power - 1, mod)) % mod;     return PowerMod((base * base) % mod, power >> 1, mod);   }   int Log(long long num, long long base) {     int ret = 0;     while (num) {       ++ret;       num /= base;     }     return ret;   }   int Count(long long mask) {     int ret = 0;     while (mask) {       if (mask & 1) ++ret;       mask >>= 1;     }     return ret;   }   inline void run() {     int n, k, ans, sum;     scanf( %d%d , &n, &k);     ans = n, sum = (n << 1);     while (true) {       if (sum >= k) break;       if (!n) break;       --ans, ++sum, --n;     }     printf( %d n , ans);   }   int main() {     ios_base::sync_with_stdio(false);     cin.tie(nullptr), cout.tie(nullptr);     run();     return 0;   }   