import sys
from collections import defaultdict

def main():
    N, M = map(int, sys.stdin.readline().split())
    operations = []
    for _ in range(M):
        B, C = map(int, sys.stdin.readline().split())
        if C > B:
            operations.append((B, C))
    
    S = set()
    edges = defaultdict(list)
    for B, C in operations:
        edges[B].append(C)
        S.add(B)
        S.add(C)
    
    sorted_S = sorted(S, reverse=True)
    max_reach = {x: x for x in S}
    
    for x in sorted_S:
        if x in edges:
            max_val = 0
            for y in edges[x]:
                if max_reach[y] > max_val:
                    max_val = max_reach[y]
            max_reach[x] = max(x, max_val)
    
    sum_S_contribution = sum(max_reach[x] for x in S)
    sum_in_S = sum(S)
    sum_total = N * (N + 1) // 2
    sum_out_S = sum_total - sum_in_S
    total = sum_S_contribution + sum_out_S
    print(total)

if __name__ == "__main__":
    main()