#pragma GCC optimize ("Ofast")

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/rope>

using namespace __gnu_pbds;
using namespace __gnu_cxx;
using namespace std;

#define int long long
#define double long double
#define Int signed
#define vi vector<int>
#define vI vector<Int>
#define vvi vector<vi>
#define vvI vector<vI>
#define vd vector<double>
#define vvd vector<vd>
#define pii pair<int, int>
#define vpii vector<pii>
#define vvpii vector<vpii>
#define mii map<int, int>
#define unordered_map gp_hash_table

#define OVERLOADED_MACRO(M, ...) _OVR(M, _COUNT_ARGS(__VA_ARGS__)) (__VA_ARGS__)
#define _OVR(macroName, number_of_args)   _OVR_EXPAND(macroName, number_of_args)
#define _OVR_EXPAND(macroName, number_of_args)    macroName##number_of_args

#define _COUNT_ARGS(...)  _ARG_PATTERN_MATCH(__VA_ARGS__, 9,8,7,6,5,4,3,2,1)
#define _ARG_PATTERN_MATCH(_1,_2,_3,_4,_5,_6,_7,_8,_9, N, ...)   N

#define rep(...) OVERLOADED_MACRO(rep, __VA_ARGS__)
#define repd(...) OVERLOADED_MACRO(repd, __VA_ARGS__)

#define rep3(i, a, b) for (int i = a; i < b; ++i)
#define rep2(i, n) rep3(i, 0, n)
#define repd3(i, a, b) for(int i = b - 1; i >= a; --i)
#define repd2(i, n) repd3(i, 0, n)
#define rep4(i, a, b, c) for(int i = a; i < b; i += c)

#define F first
#define S second

#define fastio ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define pb push_back
#define mp make_pair
#define eb emplace_back
#define all(v) v.begin(),v.end()

#define bitcount __builtin_popcountll
//for trailing 1s, do trailing0(n + 1)
#define leading0 __builtin_clzll
#define trailing0 __builtin_ctzll
#define isodd(n) (n & 1)
#define iseven(n) (!(n & 1))

#define sz(v) ((int) v.size())
#define del_rep(v) sort(all(v)); v.erase(unique(all(v)), v.end());
#define checkbit(n, b) ((n >> b) & 1)

#ifdef DEBUG
#define debug(args...) {\
    std::string _s = #args;\
    replace(_s.begin(), _s.end(), ',', ' ');\
    std::stringstream _ss(_s);\
    std::istream_iterator <std::string> _it(_ss);\
    err(_it, args);\
}
#define print_container(v) {\
    bool first = true; os << "[";\
    for (auto x : v) {\
        if (!first) os << ", "; os << x; first = false;\
    }\
    return os << "]";\
}
void err (std::istream_iterator <std::string> it) {}
template <typename T, typename... Args>
void err (std::istream_iterator <std::string> it, T a, Args... args) {
    std::cerr << *it << " = " << a << std::endl;
    err(++it, args...);
}
template <typename T1, typename T2> inline std::ostream& operator << (std::ostream& os, const std::pair<T1, T2>& p) { return os << "(" << p.first << ", " << p.second << ")"; }
template <typename T> inline std::ostream &operator << (std::ostream & os, const std::vector<T>& v) { print_container(v); }
template <typename T> inline std::ostream &operator << (std::ostream & os, const std::set<T>& v) { print_container(v); }
template <typename T1, typename T2> inline std::ostream &operator << (std::ostream & os, const std::map<T1, T2>& v) { print_container(v); }
template <typename T1, typename T2, class C> inline std::ostream &operator << (std::ostream & os, const unordered_map<T1, T2, C>& v) { print_container(v); }
template <typename T, class C> inline std::ostream &operator << (std::ostream & os, const unordered_set<T, C>& v) { print_container(v); }
template <typename T1, typename T2> inline std::ostream &operator << (std::ostream & os, const std::multimap<T1, T2>& v) { print_container(v); }
template <typename T> inline std::ostream &operator << (std::ostream & os, const std::multiset<T>& v) { print_container(v); }
#else
#define debug(args...) 0
#endif

//order_of_key(k) - number of elements e such that func(e, k) returns true, where func is less or less_equal
//find_by_order(k) - kth element in the set counting from 0
//
typedef tree <int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;
typedef tree <int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_multiset;

const int INF = 1e9;
const int LINF = INF * INF;
const double EPS = 1e-9;
const double PI = acosl(-1);
const int mod = 1e9 + 7;
const int maxn = 5e5 + 5;
const int maxa = 1e6 + 5;
const int logmax = 25;

//older machines
//use only for non-negative u, v
int32_t gcd (int32_t u, int32_t v) {
    int32_t shift;
    if (u == 0) return v;
    if (v == 0) return u;
    shift = __builtin_ctz(u | v);
    u >>= __builtin_ctz(u);
    do {
        v >>= __builtin_ctz(v);
        if (u > v) {
            swap(u, v);
        }
        v -= u;
    } while (v);
    return u << shift;
}

//use only for non-negative u, v
long long gcd (long long u, long long v) {
    int32_t shift;
    if (u == 0 || v == 0) return u + v;
    shift = __builtin_ctzll(u | v);
    u >>= __builtin_ctzll(u);
    do {
        v >>= __builtin_ctzll(v);
        if (u > v) {
            swap(u, v);
        }
        v -= u;
    } while (v);
    return u << shift;
}

struct custom_hash {
    // http://xorshift.di.unimi.it/splitmix64.c
    static uint64_t splitmix64(uint64_t x) {
        x += 0x9e3779b97f4a7c15;
        x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
        x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
        return x ^ (x >> 31);
    }
    size_t operator()(uint64_t x) const {
        static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
        return splitmix64(x + FIXED_RANDOM);
    }
    size_t operator()(pair<Int, int> x) const { 
        static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
        return splitmix64(FIXED_RANDOM + 31 * x.first + x.second);
    }
};

namespace IO {
    const int BUFFER_SIZE = 1 << 15;
    char input_buffer[BUFFER_SIZE];
    int input_pos = 0, input_len = 0;
    char output_buffer[BUFFER_SIZE];
    int output_pos = 0;
    char number_buffer[100];
    uint8_t lookup[100];
    void _update_input_buffer() {
        input_len = fread(input_buffer, sizeof(char), BUFFER_SIZE, stdin);
        input_pos = 0;
        if (input_len == 0)
            input_buffer[0] = EOF;
    }
    inline char next_char(bool advance = true) {
        if (input_pos >= input_len)
            _update_input_buffer();

        return input_buffer[advance ? input_pos++ : input_pos];
    }

    template<typename T>
        inline void read_int(T &number) {
            bool negative = false;
            number = 0;

            while (!isdigit(next_char(false)))
                if (next_char() == '-')
                    negative = true;

            do {
                number = 10 * number + (next_char() - '0');
            } while (isdigit(next_char(false)));

            if (negative)
                number = -number;
        }

    template<typename T, typename... Args>
        inline void read_int(T &number, Args &... args) {
            read_int(number);
            read_int(args...);
        }

    void _flush_output() {
        fwrite(output_buffer, sizeof(char), output_pos, stdout);
        output_pos = 0;
    }

    inline void write_char(char c) {
        if (output_pos == BUFFER_SIZE)
            _flush_output();

        output_buffer[output_pos++] = c;
    }

    template<typename T>
        inline void write_int(T number, char after = '\0') {
            if (number < 0) {
                write_char('-');
                number = -number;
            }
            int length = 0;
            while (number >= 10) {
                uint8_t lookup_value = lookup[number % 100];
                number /= 100;
                number_buffer[length++] = (lookup_value & 15) + '0';
                number_buffer[length++] = (lookup_value >> 4) + '0';
            }
            if (number != 0 || length == 0)
                write_char(number + '0');
            for (int i = length - 1; i >= 0; i--)
                write_char(number_buffer[i]);
            if (after)
                write_char(after);
        }
    void IOinit() {
        // Make sure _flush_output() is called at the end of the program.
        bool exit_success = atexit(_flush_output) == 0;
        assert(exit_success);
        for (int i = 0; i < 100; i++)
            lookup[i] = (i / 10 << 4) + i % 10;
    }
}

using namespace IO;

template <typename T>
T pwr (T a, int n = 1, T id = 1) {
    T ans = id;
    while(n) {
        if(n & 1) ans *= a;
        a *= a;
        n >>= 1;
    }
    return ans;
}

void solve() {
    int l, r, d, ans = 0;
    cin >> l >> r >> d;
    rep(i, l, r + 1) {
        if (i % d == 0) ans++;
    }
    cout << ans << "\n";
}

signed main(){
    //IOinit();
    fastio;
    cout << setprecision(10) << fixed;
    int t = 1;
    //cin >> t;
    while (t--) {
        solve();
    }
    //_flush_output();
    return 0;
}



Measured memory_bytes: 3608