#include<bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
#define lli long long int
#define ulli unsigned long long int
#define ld long double
#define fi first
#define se second
#define pb push_back
#define mp make_pair
#define loop(i,a,b) for(lli i=a;i<b;i++)
#define initialize(array,size,value) for(lli i=0;i<size;i++) array[i]=value
#define couta(array,size) for(lli i=0;i<size;i++) cout<<array[i]<<" "
#define vl vector<lli>
#define vp vector< pair <lli,lli> >
#define sl set<lli>
#define msp multiset < pair < long long , long long > > S;
#define pll pair<lli, lli>
#define mll map<lli, lli>            //for( map<lli, lli>::iterator i=temp.begin();i!=temp.end();i++)cout<<i->fi<<" "<<i->se<<endl;
#define mvl map<lli, vl>
#define umll unordered_map<lli, lli>
#define vt vector<pair<lli, pll >  >
#define vf vector<pair<pll,pll > >
#define qu queue<lli>
#define pq priority_queue<lli>
#define dq deque <lli>
#define ptr vector<lli>::iterator
#define bs(array,x) binary_search(array.begin(),array.end(),x) // also valid for set and multiset
#define lb(array,x) lower_bound(array.begin(),array.end(),x)
#define ub(array,x) upper_bound(array.begin(),array.end(),x)
#define nobw(array,i,j) upper_bound(array.begin(), array.end(), j)-lower_bound(array.begin(), array.end(), i) //number of numbers between i & j
#define vc clear()
#define endl '\n'
#define sp system("pause");
#define INF 9223372036854775807
#define MINF -9223372036854775808
typedef tree<pll,null_type,less<pll>,rb_tree_tag,
tree_order_statistics_node_update> indexed_set;
//string binary = bitset<32>(n).to_string(); 
int A[9];          //power of 2 here 1 to 8
int tre[17];
int lazy[17];
void build(int node, int start, int end)
{
    if(start == end)
    {
        // Leaf node will have a single element
        tre[node] = A[start];
    }
    else
    {
        int mid = (start + end) / 2;
        // Recurse on the left child
        build(2*node, start, mid);
        // Recurse on the right child
        build(2*node+1, mid+1, end);
        // Internal node will have the sum of both of its children
        tre[node] = tre[2*node] + tre[2*node+1];
    }
}
void updateRange(int node, int start, int end, int l, int r, int val)
{
    if(lazy[node] != 0)
    { 
        // This node needs to be updated
        tre[node] += (end - start + 1) * lazy[node];    // Update it
        if(start != end)
        {
            lazy[node*2] += lazy[node];                  // Mark child as lazy
            lazy[node*2+1] += lazy[node];                // Mark child as lazy
        }
        lazy[node] = 0;                                  // Reset it
    }
    if(start > end or start > r or end < l)              // Current segment is not within range [l, r]
        return;
    if(start >= l and end <= r)
    {
        // Segment is fully within range
        tre[node] += (end - start + 1) * val;
        if(start != end)
        {
            // Not leaf node
            lazy[node*2] += val;
            lazy[node*2+1] += val;
        }
        return;
    }
    int mid = (start + end) / 2;
    updateRange(node*2, start, mid, l, r, val);        // Updating left child
    updateRange(node*2 + 1, mid + 1, end, l, r, val);   // Updating right child
    tre[node] = tre[node*2] + tre[node*2+1];        // Updating root with max value 
}

int queryRange(int node, int start, int end, int l, int r)
{
    if(start > end or start > r or end < l)
        return 0;         // Out of range
    if(lazy[node] != 0)
    {
        // This node needs to be updated
        tre[node] += (end - start + 1) * lazy[node];            // Update it
        if(start != end)
        {
            lazy[node*2] += lazy[node];         // Mark child as lazy
            lazy[node*2+1] += lazy[node];    // Mark child as lazy
        }
        lazy[node] = 0;                 // Reset it
    }
    if(start >= l and end <= r)             // Current segment is totally within range [l, r]
        return tre[node];
    int mid = (start + end) / 2;
    int p1 = queryRange(node*2, start, mid, l, r);         // Query left child
    int p2 = queryRange(node*2 + 1, mid + 1, end, l, r); // Query right child
    return (p1 + p2);
}
int main()
{
 	ios::sync_with_stdio(0);
    cin.tie(0);
    lli a,b;
    cin>>a>>b;
    a*=3;
    cout<<(a+b)/2;
}




Measured memory_bytes: 256