#include <bits/stdc++.h>
long long cmpfunc(const void* a, const void* b) {
  return (*(long long*)a - *(long long*)b);
}
int main(void) {
  long long int test, i, j, n, count, flag = 0, o1 = 0, o2 = 0, b1, x, m, l,
                                      max, sum2, min, f, c, r, o, sum1, sum = 0,
                                      y, a, b, count1 = 0, a2, b2;
  printf("%lld%lld", &n, &m);
  printf("%lld", ((n * 3) + m) / 2);
  return 0;
}
