#include <iostream>
#include <fstream>
using namespace std;
ifstream f("bacterie.in");
ofstream g("bacterie.out");
int main()
{
long long unsigned n, m, s=0, i;
f>>n>>m;
if(n==m)
for(i=0; i<m; i++)
s=s+i;
if(n>m)
for(i=0; i<m; i++)
s=s+n-m+i;
if(m>n)
for(i=0; i<n; i++)
s=s+m-n+i;
g<<s;
f.close();
g.close();
}
dar vezi ca la ultima depaseste limita de timp si imi da doar 85p pe pbinfo. Daca are ceva sterg raspunsul
