#define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES

#include <bits/stdc++.h>
using namespace std;
using i8  = int8_t;  using u8  = uint8_t;
using i16 = int16_t; using u16 = uint16_t;
using i32 = int32_t; using u32 = uint32_t;
using i64 = int64_t; using u64 = uint64_t;
using f32 = float_t; using f64 = double_t;
using usize = size_t;using str = string;
template <class T> using vec = vector<T>;
using wdgraph = vec<vec<pair<i32, i32>>>;
#define times(n, i) for (i32 i = 0; i < (n); i++)
#define range(n, m, i) for (i32 i = (n); i < (m); i++)
#define upto(n, m, i) for (i32 i = (n); i <= (m); i++)
#define downto(n, m, i) for (i32 i = (n); i >= (m); i--)
#define foreach(xs, x) for (auto &x : (xs))
#define all(xs) (xs).begin(), (xs).end()
#define sortall(xs) sort(all(xs))
#define reverseall(xs) reverse(all(xs))
#define uniqueall(xs) (xs).erase(unique(all(xs)), (xs).end())
#define maximum(xs) *max_element(all(xs))
#define minimum(xs) *min_element(all(xs))
const i64 MOD = 1000000007;

bool isKadomatsu(i32 a, i32 b, i32 c) {
    if (a == b || b == c || a == c)
        return false;
    return a < b && b > c || a > b && b < c;
}

i32 main()
{
    vec<i32> D;
    times(7, i) {
        i32 d; cin >> d;
        D.emplace_back(d);
    }
    bool ans = false;
    do {
        bool isK = true;
        upto(0, 4, i) {
            isK = isK && isKadomatsu(D[i], D[i+1], D[i+2]) && D[i] < D[i+2];
        }
        if (isK) {
            ans = true;
            break;
        }
    } while (next_permutation(D.begin(), D.end()));

    cout << (ans ? "YES" : "NO") << endl;
    return 0;
}