#include <bits/stdc++.h> #define MOD 1000000007 using namespace std; typedef long long int ll; typedef pair<int,int> pii; typedef pair<int, pii> piii; const int INF = 1e9+1; const int MAXN = 1e5+10; int main() { ll a,b; scanf("%lld%lld",&a,&b); if(b<=3)return !puts("0"); if(a<=2)a = 4; b = b/2; a = (a+1)/2-1; ll sum = b*(b+1)-a*(a+1); printf("%lld",sum); return 0; }

polygon.cpp: In function 'int main()':
polygon.cpp:15:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%lld%lld",&a,&b);
     ~~~~~^~~~~~~~~~~~~~~~~~