include <bits/stdc++.h>

using namespace std;

// clang-format off
// <----------------------- Macros Start Here ----------------------->

define FastIO ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)

define el '\n'

define MOD1 1000000007

define MOD2 998244353

define INF numeric_limits<ll>::max()

// Container Macros

define all(x) x.begin(), x.end()

define rall(x) x.rbegin(), x.rend()

define popFront(x) x.erase(x.begin())

define mp(x, y) make_pair(x, y)

define pb push_back

define ppb pop_back

define ff first

define ss second

// Typedefs Here
typedef long long int ll;
typedef unsigned long long int ull;
typedef long double lld;
typedef vector <ll> vl;
typedef vector <pair \<ll, ll> > vll;
typedef pair <ll, ll> pll;
typedef priority_queue<ll> priQueNorm;
typedef priority_queue<ll, vector\<ll>, greater\<ll> > priQueVec;

// <----------------------- Macros End Here ----------------------->

// <----------------------- Debug Utils Start Here ----------------------->

ifndef ONLINE_JUDGE

define debug(x) cerr << #x <<" "; _print(x); cerr << el;

else

define debug(x)

endif

void _print(ll t) { cerr << t; }
void _print(int t) { cerr << t; }
void _print(string t) { cerr << t; }
void _print(char t) { cerr << t; }
void _print(lld t) { cerr << t; }
void _print(double t) { cerr << t; }
void _print(ull t) { cerr << t; }

template <class T, class V> void _print(pair<T, V> p);
template <class T> void _print(vector<T> v);
template <class T> void _print(set<T> v);
template <class T, class V> void _print(map<T, V> v);
template <class T> void _print(multiset<T> v);
template <class T, class V> void _print(pair<T, V> p) { cerr << "{"; _print(p.ff); cerr << ","; _print(p.ss); cerr << "}"; }
template <class T> void _print(vector<T> v) { cerr << "[ "; for (T i : v) { _print(i); cerr << " "; } cerr << "]"; }
template <class T> void _print(set<T> v) { cerr << "[ "; for (T i : v) { _print(i); cerr << " "; } cerr << "]"; }
template <class T> void _print(multiset<T> v) { cerr << "[ "; for (T i : v) { _print(i); cerr << " "; } cerr << "]"; }
template <class T, class V> void _print(map<T, V> v) { cerr << "[ "; for (auto i : v) { _print(i); cerr << " "; } cerr << "]"; }

// Operator overloads
template<typename T1, typename T2> // cin >> pair<T1, T2>
istream& operator>>(istream &istream, pair<T1, T2> &p) { return (istream >> p.first >> p.second); }
template<typename T> // cin >> vector<T>
istream& operator>>(istream &istream, vector<T> &v) { for (auto &it : v) cin >> it; return istream; }
template<typename T1, typename T2> // cout << pair<T1, T2>
ostream& operator<<(ostream &ostream, const pair<T1, T2> &p) { return (ostream << p.first << " " << p.second << el); }
template<typename T> // cout << vector<T>
ostream& operator<<(ostream &ostream, const vector<T> &c) { for (auto &it : c) cout << it << " "; return ostream; }

// <----------------------- Debug Utils End Here ----------------------->

// <----------------------- Predefined Goodies Start Here ----------------------->

ll GCD(ll a, ll b) {if (b > a) {return GCD(b, a);} if (b == 0) {return a;} return GCD(b, a % b);}
ll LCM(ll a, ll b) { return (a / GCD(a, b)) * b; }
ll pwr(ll a, ll b, ll mod) {ll res = 1; while (b > 0) {if (b & 1)res = (res * a) % mod; a = (a * a) % mod; b = b >> 1;} return res;}
ll mminvprime(ll a, ll b) {return pwr(a, b - 2, b);}
ll modAdd(ll a, ll b, ll m) {a = a % m; b = b % m; return (((a + b) % m) + m) % m;}
ll modMul(ll a, ll b, ll m) {a = a % m; b = b % m; return (((a * b) % m) + m) % m;}
ll modSub(ll a, ll b, ll m) {a = a % m; b = b % m; return (((a - b) % m) + m) % m;}
ll modDiv(ll a, ll b, ll m) {a = a % m; b = b % m; return (modMul(a, mminvprime(b, m), m) + m) % m;} //only for prime m
bool isPrime(ll n) { if(n < 2) return false; for(ll k = 2; k * k <= n; k++) if(n % k == 0) return false; return true; }

// <----------------------- Predefined Goodies End Here ----------------------->

// clang-format on

int32_t main() {

ifndef ONLINE_JUDGE

freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
freopen("error.txt", "w", stderr);
clock_t startClock = clock();

endif

FastIO;
istream &in(cin);
ostream &out(cout);
/*
Start Coding Here
*/

int n, x;
cin >> n >> x;
vll a(n);

for (int i = 0; i < n; ++i) {
    cin >> a[i];
}

int i = 1, j = N;
while (i < j) {
    if (a[i] + a[j] == x) {
        cout << i << " " << j;
        return 0;
    }
    if (a[i] + a[j] < x)
        i += 1;
    else
        j -= 1;
}
cout << "IMPOSSIBLE";

/*
Code Ends Here
*/

ifndef ONLINE_JUDGE

clock_t endClock = clock();
double timeTaken = double(endClock - startClock) / double(CLOCKS_PER_SEC);
cout << fixed << setprecision(7);
cout << "Time Taken: " << timeTaken << " Sec";

endif

return 0;

}