import sys
from collections import deque

def main():
    data = sys.stdin.buffer.read().split()
    idx = 0
    N = int(data[idx]); idx += 1
    M = int(data[idx]); idx += 1
    K = int(data[idx]); idx += 1
    adj = [[] for _ in range(N+1)]
    radj = [[] for _ in range(N+1)]
    for _ in range(M):
        u = int(data[idx]); idx += 1
        v = int(data[idx]); idx += 1
        adj[u].append(v)
        radj[v].append(u)

    R = [False]*(N+1)
    R[1] = True
    stk = [1]
    while stk:
        u = stk.pop()
        for v in adj[u]:
            if not R[v]:
                R[v] = True
                stk.append(v)

    order = []
    visited = [False]*(N+1)
    visited[1] = True
    node_stack = [1]
    it_stack = [iter(adj[1])]
    while node_stack:
        found = False
        for v in it_stack[-1]:
            if R[v] and not visited[v]:
                visited[v] = True
                node_stack.append(v)
                it_stack.append(iter(adj[v]))
                found = True
                break
        if not found:
            order.append(node_stack.pop())
            it_stack.pop()

    comp = [0]*(N+1)
    c = 0
    for u in reversed(order):
        if comp[u] == 0:
            c += 1
            stk = [u]
            comp[u] = c
            while stk:
                x = stk.pop()
                for y in radj[x]:
                    if R[y] and comp[y] == 0:
                        comp[y] = c
                        stk.append(y)
    num_scc = c

    has_next = [False]*(num_scc+2)
    for u in range(1, N+1):
        if not R[u]: continue
        cu = comp[u]
        for v in adj[u]:
            if not R[v]: continue
            cv = comp[v]
            if cv == cu + 1:
                has_next[cu] = True

    for i in range(1, num_scc):
        if not has_next[i]:
            print("No"); return

    scc1 = comp[1]
    color = [-1]*(N+1)
    color[1] = 0
    q = deque([1])
    odd = False
    while q:
        u = q.popleft()
        cc = color[u]
        for v in adj[u]:
            if comp[v] != scc1: continue
            if color[v] == -1:
                color[v] = 1 - cc
                q.append(v)
            elif color[v] == cc:
                odd = True

    print("Yes" if odd else "No")

main()