#pragma region Template
#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cstdlib>
#include <queue>
#include <vector>
#include <map>
#include <cmath>
#include <string>
#include <cstring>
#include <utility>
#include <stack>
#include <set>
#include <algorithm>
#include <bitset>
#include <functional>
#include <ctime>
#include <cassert>
#include <valarray>
#include <unordered_map>
#include <unordered_set>
#include <random>
#include <complex>
#include <regex>
#include <numeric>
#pragma comment(linker, "/STACK:167772160")

using namespace std;

template <typename T, typename Q>
ostream& operator<<(ostream& os, pair<T, Q> p)
{
	return (os << '(' << p.first << ", " << p.second << ')');
}

#define mp make_pair
#define rand govno_ebanoe
#ifdef LOCAL
#define eprintf(...) fprintf(stderr, __VA_ARGS__)
#define print_var(x) cerr << #x << " : " << (x) << endl
#define print_array(arr, len) {cerr << #arr << " : "; for(int i = 0; i < len; ++i) cerr << arr[i] << ' '; cerr << endl;}
#define print_2d_array(arr, len1, len2) {cerr << #arr << endl; for(int i = 0; i < len1; ++i, cerr << endl) for(int j = 0; j < len2; ++j) cerr << arr[i][j] << ' ';}
#define print_iterable(i) {cerr << #i << " : "; for(auto e : i) cerr << e << ' '; cerr << endl;}
#define print_new_line() cerr << endl
#else
#define eprintf(...) (void)0
#define print_var(x) (void)0
#define print_array(arr, len) {}
#define print_2d_array(arr, len1, len2) {}
#define print_iterable(i) {}
#define print_new_line() (void)0
#endif

typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
typedef unsigned int uint;
typedef pair<int, int> pii;
typedef pair<ll, int> pli;
typedef pair<ll, ll> pll;

const int INF = (int)1e9 + 10;
const ll LINF = ll(2e18) + 10;
const double PI = acosl(-1);
const double eps = 1e-8;
const ld EPS = 1e-12;
#pragma endregion

#ifdef LOCAL
#define ERR_CATCH
//#define NOERR
#endif

const int N = 1e5 + 10;
int n, m;
vector<int> go[N];
char used[N];
char col[N];
int b, w;

int dfs(int v)
{
	if (used[v])
		return 0;
	used[v] = true;
	int sz = 1;
	for (auto e : go[v])
		sz += dfs(e);
	return sz;
}

bool colorize(int v)
{
	if (col[v] == 1)
		++b;
	else
		++w;
	for (auto e : go[v])
		if (col[e] == col[v])
			return false;
		else if(col[e] == 0)
		{
			col[e] = 3 - col[v];
			if (!colorize(e))
				return false;
		}
	return true;
}

void solve()
{
	scanf("%d%d", &n, &m);
	for(int i = 0; i < m; ++i)
	{
		int a, b;
		scanf("%d%d", &a, &b);
		--a, --b;
		go[a].push_back(b);
		go[b].push_back(a);
	}
	ll ans = 0;
	for (int i = 0; i < n; ++i)
		if (!used[i])
		{
			b = 0;
			w = 0;
			ll sz = dfs(i);
			col[i] = 1;
			if (colorize(i))
				ans += (ll)b * w;
			else
				ans += sz * (sz - 1) / 2;
		}
	printf("%lld\n", ans - m);
}

int main()
{
#ifdef LOCAL
	freopen("input.txt", "r", stdin);
	//freopen("output.txt", "w", stdout);
#ifdef NOERR
	freopen("err.txt", "w", stderr);
#endif
#else
	//freopen("sum.in", "r", stdin);
	//freopen("sum.out", "w", stdout);
#endif

#ifdef ERR_CATCH
	try
	{
#endif

#ifdef ST
		while (true)
			solve();
#endif

#ifdef CASES
#define MULTITEST
#endif

#ifdef MULTITEST
		int t;
		scanf("%d", &t);
		char endl1[5];
		fgets(endl1, 5, stdin);
		for (int i = 0; i < t; ++i)
		{
#ifdef CASES
			printf("Case #%d: ", i + 1);
#endif
			solve();
#ifdef CASES
			eprintf("Passed case #%d:\n", i + 1);
#endif
		}
#else
		solve();
#endif

#ifdef ERR_CATCH
	}
	catch (logic_error e)
	{
		print_var(e.what());
		puts("___________________________________________________________________________");
		exit(0);
	}
#endif
#ifdef LOCAL
	eprintf("\n\nTime: %.3lf\n", double(clock()) / CLOCKS_PER_SEC);
#endif
}

Measured memory_bytes: 6400