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//Krzysztof Pieprzak
#include <bits/stdc++.h>
#include "message.h"
#include "teatr.h"

using namespace std;

typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
typedef unsigned int uint;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef pair<int,int> pii;
typedef pair<long long, long long> pll;
typedef vector<pii> vpii;
typedef vector<pll> vpll;

#define Size(x) (int)x.size()
#define VAR(v,n) auto v = (n)
#define FOR(i,a,b) for(VAR(i,a); i < (b); ++i)
#define FORE(i,a,b) for(VAR(i,a); i <= (b); ++i)
#define FORREV(i,a,b) for(VAR(i,b); i >= (a); --i)
#define FORSTEP(i,a,b,step) for(VAR(i,a); i < (b); i += (step))
#define FOREACH(i,c) for(auto i : (c))
#define FOREACHS(i,c,n) for(VAR(i,&(c)[0]); i-(c)<(n); ++i)
#define ALL(x) x.begin(),x.end()
#define CLEAR(t) memset(t, 0, sizeof(t))
#define F first
#define S second
#define MP make_pair
#define PUB push_back
#define POB pop_back
#define pieprzu ios_base::sync_with_stdio(0);

const int    INF = 1000000001;
const double EPS = 10e-9;

const int POWER_OF_2_GREATER_THAN_MAX_LOCAL_N = 1 << 20;
const int START = POWER_OF_2_GREATER_THAN_MAX_LOCAL_N;
const int TREE_SIZE = 2 * POWER_OF_2_GREATER_THAN_MAX_LOCAL_N;

ll tree[TREE_SIZE];

int numberOfNodes;
int myNodeId;

int globalN;
int myStart;
int myN;

void read() {
    numberOfNodes = NumberOfNodes();
    myNodeId = MyNodeId();

    globalN = GetN();
    int elementsNumberPerNode = globalN / numberOfNodes;
    myStart = myNodeId * elementsNumberPerNode;
    myN = elementsNumberPerNode;

    if (myNodeId == numberOfNodes - 1) {
        myN += globalN % numberOfNodes;
    }
}

void initTree() {
    FOR (i, 0, myStart) {
        ++tree[START + GetElement(i)];
    }

    FORREV (i, 1, START - 1) {
        tree[i] = tree[i << 1] + tree[(i << 1) | 1];
    }
}

ll countGreater(int element) {
    ll result = 0;
    for (int i = START + element; i > 0; i >>= 1) {
        if ((i & 1) == 0) {
            result += tree[i + 1];
        }
    }
    return result;
}

void addElement(int element) {
    for (int i = START + element; i > 0; i >>= 1) {
        ++tree[i];
    }

}

ll process() {
    int myEnd = myStart + myN;
    int element;
    ll result = 0;
    FOR (i, myStart, myEnd) {
        element = GetElement(i);
        result += countGreater(element);
        addElement(element);
    }

    return result;
}

void rob(int test) {
    read();
    initTree();
    ll result = process();

    if (myNodeId != 0) {
        PutLL(0, result);
        Send(0);
    } else {
        FOR (i, 1, numberOfNodes) {
            Receive(i);
            result += GetLL(i);
        }
    }

    if (myNodeId == 0) {
        printf("%lld\n", result);
    }
}

int main() {
    int test = 1;
    //scanf("%d", &test);

    FORE (i, 1, test) rob(i);

    return 0;
}