import std.stdio, std.array, std.conv, std.typecons, std.algorithm;

T diff(T)(const ref T a, const ref T b) { return a > b ? a - b : b - a; }

void main() {
    immutable ip = readln.split.to!(ulong[]);
    immutable a = ip[0], p = ip[1];

    writeln((a*3+p)/2);
}
