import sys
input = sys.stdin.readline

from bisect import *
from copy import deepcopy
def compress(lst):
    '''
    B: lstを座圧したリスト
    idx_to_val: indexから元の値を取得するリスト
    val_to_idx: 元の値からindexを取得する辞書
    '''
    B = []
    val_to_idx = {}
    idx_to_val = deepcopy(lst)
    idx_to_val = list(set(idx_to_val))
    idx_to_val.sort()
    for i in range(len(lst)):
        ind = bisect_left(idx_to_val, lst[i])
        B.append(ind)
    for i in range(len(B)):
        val_to_idx[lst[i]] = B[i]
    return B, idx_to_val, val_to_idx


class DirectedGraph():
    def __init__(self, N):
        self.N = N
        self.G = [[] for i in range(N)]
        self.rG = [[] for i in range(N)]
        self.order = []
        self.used1 = [0] * N
        self.used2 = [0] * N
        self.group = [-1] * N
        self.label = 0
        self.seen = [0] * N
        self.Edge = set()

    def add_edge(self, u, v):
        #多重辺は排除する
        if (u, v) not in self.Edge:
            self.G[u].append(v)
            self.rG[v].append(u)
            self.Edge.add((u, v))

    def dfs(self, s):
        stack = [~s, s]
        while stack:
            u = stack.pop()
            if u >= 0:
                if self.used1[u]:
                    continue
                self.used1[u] = 1
                for v in self.G[u]:
                    if self.used1[v]:
                        continue
                    stack.append(~v)
                    stack.append(v)
            else:
                u = ~u
                if self.seen[u]:
                    continue
                self.seen[u]= 1
                self.order.append(u)

    def rdfs(self, s, num):
        stack = [s]
        while stack:
            u = stack.pop()
            if u >= 0:
                self.used2[u] = 1
                self.group[u] = num
                for v in self.rG[u]:
                    if self.used2[v]:
                        continue
                    stack.append(v)

    def scc(self):
        for i in range(self.N):
            if self.used1[i]:
                continue
            self.dfs(i)
        for s in reversed(self.order):
            if self.used2[s]:
                continue
            self.rdfs(s, self.label)
            self.label += 1
        return self.label, self.group

    def construct(self):
        nG = [set() for _ in range(self.label)]
        mem = [[] for i in range(self.label)]
        for s in range(self.N):
            now = self.group[s]
            for u in self.G[s]:
                if now == self.group[u]:
                    continue
                nG[now].add(self.group[u])
            mem[now].append(s)
        return nG, mem


N, M = map(int, input().split())
B, C = [0] * M, [0] * M
for i in range(M):
    B[i], C[i] = map(int, input().split())
    
D, itov, _ = compress(B + C)
B, C = D[:M], D[M:]
K = max(D) + 1
G = DirectedGraph(K)
for i in range(M):
    G.add_edge(C[i], B[i])
    
L, _ = G.scc()
nG, mem = G.construct()
ans = N * (N + 1) // 2
dp = [0] * L
for i in range(L):
    dp[i] = max(mem[i])
    
for i in range(L):
    for u in nG[i]:
        dp[u] = max(dp[u], dp[i])
        
    for m in mem[i]:
        ans += max(0, itov[dp[i]] - itov[m])
        
print(ans)