NR==1{
    n=$1
}
NR>1{
    broken[$1]=1
}
END{
    MOD=1000000007
    dp[-1] = 0
    dp[0] = 1
    for(i=1; i<=n; ++i) {
        if (broken[i]) {
            dp[i] = 0;
            # print i, "BROKEN"
        } else {
            dp[i] = (dp[i-1] + dp[i-2]) % MOD
            # print i, dp[i], " = ", dp[i-1] + dp[i-2]
        }
        # del dp[i-2]
    }
    print dp[n]
}
