func_code_string: #include <bits/stdc++.h>   using namespace std;   long long summ(long long n) { return (n * (n + 1)) / 2; }   long long sear(long long n, long long k) {     if (n == 1 && k == 1) return 0;     long long lo = 0, hi = n, mid;     long long sum, eaten;     while (lo <= hi) {       mid = lo + (hi - lo) / 2;       sum = summ(n - mid);       if (mid + k == sum)         return mid;       else if (mid + k > sum)         hi = mid - 1;       else         lo = mid + 1;     }     return mid;   }   int main() {     long long n, k;     cin >> n >> k;     if (n == 1 && k == 1) {       cout << 0 << endl;       return 0;     }     long long ans = sear(n, k);     cout << ans << endl;     return 0;   }   