// KNOW NOTHING!
#include <bits/stdc++.h>
#define ll long long int
#define F(i,j,k,in) for(int i=j;i<k;i+=in)
#define DF(i,j,k,in) for(int i=j;i>=k;i-=in)
#define feach(it,l) for (auto it = l.begin(); it != l.end(); ++it)
#define fall(a) a.begin(),a.end()
#define sz(x) (int)x.size()
#define szs(x) (int)x.length()
#define pb push_back
#define ub upper_bound
#define lb lower_bound
#define eq equal_range
#define fs first
#define ss second
#define ins insert
#define mkp make_pair
#define endl "\n"
using namespace std;
typedef vector<ll> vll;
typedef vector<int> vin;
typedef vector<char> vch;
typedef vector<string> vst;
typedef set<ll> sll;
typedef set<int> sint;
typedef set<char> sch;
typedef set<string> sst;
typedef queue<ll> qll;
typedef queue<int> qin;
typedef deque<ll> dqll;
typedef deque<int> dqint;
typedef priority_queue<ll> pqll;
typedef priority_queue<int> pqin;
typedef map<ll,ll> mpll;
typedef map<int,int> mpin;
typedef pair<ll,ll> pll;
typedef pair<int,int> pin;
const ll MOD=1000000007;
const long double PI=3.1415926535897932384626433832795;
ll pwr(ll b,ll p){ll res=1;while(p){if(p&1) {res*=b; p--;}else{b*=b; p>>=1;}}return res;}
ll mpwr(ll b,ll p){ll res=1;while(p){if(p&1) {res=(res*b)%MOD; p--;}else{b=(b*b)%MOD; p>>=1;}}return res;}
int msb (int n) {return 31-__builtin_clz(n);}
ll msbl (ll n) {return 63-__builtin_clzll(n);}
int lsb (int n) {return __builtin_ctz(n);}
ll  lsbl (ll n) {return __builtin_ctzll(n);}
int setbit (int n) {return __builtin_popcount(n);}
ll setbitl (ll n) {return __builtin_popcountll(n);}
int main()
{
/*
freopen ("input.txt","r","stdin");
freopen ("output.txt","w","stdout");
*/
ios_base::sync_with_stdio(false) , cin.tie(NULL) , cout.tie(NULL);
ll n; cin>>n;
mpll mp;
F (i,0,n,1) {
	int a ; cin>>a;
	++mp[a%200];
}
ll cnt=0;
for (auto i : mp) {
	cnt+=((i.ss)*(i.ss-1))/2;
}
cout<<cnt;
return 0;
}
/* What we know is a drop , but what we don't know is an ocean !*/
#include <unordered_map>
#include <unordered_set>
#include <algorithm>
#include <iostream>
#include <iostream>
#include <fstream>
#include <numeric>
#include <cstring>
#include <cassert>
#include <string>
#include <vector>
#include <queue>
#include <deque>
#include <cmath>
#include <set>
#include <map>
#include <functional>
#include <bitset>
#include <iomanip>
#include <stack>
#include <list>
#include <cstdint>
#include <chrono>
#include <hash_map>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/detail/standard_policies.hpp>

using namespace __gnu_pbds;
using namespace std;

#define     lp(i,a,n)       for(ll i=a;i<n;i++)
#define     lp2(i,n,a)      for(ll i=a-1;i>=n;i--)
#define     all(arr,n)      arr,arr+n
#define     allv(v)         (v).begin(),(v).end()
#define     rallv(v)        (v).rbegin(),(v).rend()
#define     m_p             make_pair
#define     ll              long long
#define     pii             pair<ll,ll>
#define     vi              vector<int>
#define     vll             vector<ll>
#define     vii             vector<pii>
#define     sz(x)           (int)x.size()
#define     pb              push_back
#define     endl            '\n'
#define     Endl            '\n'
#define     f               first
#define     s               second
#define     mem(dp,n)       memset(dp,n,sizeof dp)
#define     ordered_set     tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update>
template<typename T>void max_self(T &a,T b){a=max(a,b);}
template<typename T>void min_self(T &a,T b){a=min(a,b);}
int dx[] = { 1 , 0 ,-1 , 0 ,-1 ,-1 , 1 , 1 };
int dy[] = { 0 , 1 , 0 ,-1 ,-1 , 1 ,-1 , 1 };
int KnightX[] = { 2, 1, -1, -2, -2, -1, 1, 2 };
int KnightY[] = { 1, 2, 2, 1, -1, -2, -2, -1 };
void fast(){
    std::ios_base::sync_with_stdio(0);
    cin.tie(NULL);
    cout.tie(NULL);
}
vector<string> vec_splitter(string s) {
    s += ',';
    vector<string> res;
    while(!s.empty()) {
        res.push_back(s.substr(0, s.find(',')));
        s = s.substr(s.find(',') + 1);
    }
    return res;
}
void debug_out(
        vector<string> __attribute__ ((unused)) args,
        __attribute__ ((unused)) int idx,
        __attribute__ ((unused)) int LINE_NUM) { cerr << endl; }
template <typename Head, typename... Tail>
void debug_out(vector<string> args, int idx, int LINE_NUM, Head H, Tail... T) {
    if(idx > 0) cerr << ", "; else cerr << "Line(" << LINE_NUM << ") ";
    stringstream ss; ss << H;
    cerr << args[idx] << " = " << ss.str();
    debug_out(args, idx + 1, LINE_NUM, T...);
}
#define debug(...) debug_out(vec_splitter(#__VA_ARGS__), 0, __LINE__, __VA_ARGS__)
const ll mxN=1e5+1,oo=0x3f3f3f3f,MOD=1e9+7;
const long double PI = acos(-1),eps=1e-9;

void solve(){
    ll n,w;
    cin>>n>>w;
    cout<<n/w<<endl;
}

int main() {
#ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif
    fast();
    int t=1;
    //cin>>t;
    while(t--)
        solve();
    return 0;
}