Problem:
Score : 100 points

Problem Statement

We have five variables x_1, x_2, x_3, x_4, and x_5.

The variable x_i was initially assigned a value of i.

Snuke chose one of these variables and assigned it 0.

You are given the values of the five variables after this assignment.

Find out which variable Snuke assigned 0.

Constraints

The values of x_1, x_2, x_3, x_4, and x_5 given as input are a possible outcome of the assignment by Snuke.

Input

Input is given from Standard Input in the following format:

x_1 x_2 x_3 x_4 x_5

Output

If the variable Snuke assigned 0 was x_i, print the integer i.

Sample Input 1

0 2 3 4 5

Sample Output 1

1

In this case, Snuke assigned 0 to x_1, so we should print 1.

Sample Input 2

1 2 0 4 5

Sample Output 2

3

Solution in C++ (GCC 9.2.1) (judge verdict: Accepted)

#pragma region RegionDefs
#include <bits/stdc++.h>
#define rep(i,n) for(int i=0,i##_len=(n);i<i##_len;++i)
#define reps(i,l,r) for(int i=(l),i##_len=(r);i<i##_len;++i)
#define all(x) begin(x),end(x)
using namespace std;
typedef long long ll;
const ll INF = 1e9;
template<class T=ll> using V = vector<T>;
template<class T=ll> using PQ = priority_queue<T>;
template<class T=ll> using PQG = priority_queue<T, V<T>, greater<T>>;
const ll MOD = 1000000007LL;
void in() {}
template<class Head, class... Tail>
void in(Head&& head, Tail&&... tail)
{
    cin >> head;
    in(move(tail)...);
}
#define IN(...) ll __VA_ARGS__; in(__VA_ARGS__)
#define INS(T, ...) T __VA_ARGS__; in(__VA_ARGS__)
#define VIN(T, v, n) V<T> v(n); for(auto& _elem:v)cin>>_elem
template<class T>bool chmax(T &a, const T &b) {if (a<b) {a=b; return 1;} return 0;}
template<class T>bool chmin(T &a, const T &b) {if (a>b) {a=b; return 1;} return 0;}
#define y0 y__0
#define y1 y__1
#define j0 j__0
#define j1 j__1
#define YN(e) cout << ((e) ? "YES" : "NO") << endl
#define yn(e) cout << ((e) ? "Yes" : "No") << endl
#pragma endregion RegionDefs

void solve()
{
    VIN(ll, v, 5);
    rep(i, 5) {
        if (v[i] == 0) {
            cout << i+1 << endl;
        }
    }
}

int main()
{
    cin.tie(0); cout.tie(0);
    ios::sync_with_stdio(false);
    cout << setprecision(numeric_limits<double>::max_digits10);

    solve();

    return 0;
}