#include #define endl '\n' using namespace std; int n, k, cnt = 0; long long dp[70010]; int main(){ cin >> n >> k; for(int i = 1; i <= n; i++){ dp[i] = dp[i-1] + i; } for(int i = k; i <= n; i++){ long long curr = dp[i] - dp[i-k]; // 判断这个数是不是某一个数的平方 if((int)sqrt(curr) * (int)sqrt(curr) == curr){ cnt++; } } cout << cnt; return 0; }