import java.io.*;
import java.util.*;
public class Omenat {
public static void main(String[] args) {
IO io = new IO();
int y = 0;
int k = 0;
int v = 0;
int n = io.nextInt();
for (int i = 0; i < n; ++i){
int p = io.nextInt()%3;
if (p == 0){
++v;
} else if (p == 1){
++y;
if (y == 3){
y = 0;
v+=3;
}
} else {
++k;
if (k == 3){
k = 0;
v+=3;
}
}
}
while(k > 0 && y > 0){
v+=2;
--k;
--y;
}
io.println(v);
io.close();
}
}
class IO extends PrintWriter {
private InputStreamReader r;
private static final int BUFSIZE = 1 << 15;
private char[] buf;
private int bufc;
private int bufi;
private StringBuilder sb;
public IO() {
super(new BufferedOutputStream(System.out));
r = new InputStreamReader(System.in);
buf = new char[BUFSIZE];
bufc = 0;
bufi = 0;
sb = new StringBuilder();
}
private void fillBuf() throws IOException {
bufi = 0;
bufc = 0;
while(bufc == 0) {
bufc = r.read(buf, 0, BUFSIZE);
if(bufc == -1) {
bufc = 0;
return;
}
}
}
private boolean pumpBuf() throws IOException {
if(bufi == bufc) {
fillBuf();
}
return bufc != 0;
}
private boolean isDelimiter(char c) {
return c == ' ' || c == '\t' || c == '\n' || c == '\r' || c == '\f';
}
private void eatDelimiters() throws IOException {
while(true) {
if(bufi == bufc) {
fillBuf();
if(bufc == 0) throw new RuntimeException("IO: Out of input.");
}
if(!isDelimiter(buf[bufi])) break;
++bufi;
}
}
public String next() {
try {
sb.setLength(0);
eatDelimiters();
int start = bufi;
while(true) {
if(bufi == bufc) {
sb.append(buf, start, bufi - start);
fillBuf();
start = 0;
if(bufc == 0) break;
}
if(isDelimiter(buf[bufi])) break;
++bufi;
}
sb.append(buf, start, bufi - start);
return sb.toString();
} catch(IOException e) {
throw new RuntimeException("IO.next: Caught IOException.");
}
}
public int nextInt() {
try {
int ret = 0;
eatDelimiters();
boolean positive = true;
if(buf[bufi] == '-') {
++bufi;
if(!pumpBuf()) throw new RuntimeException("IO.nextInt: Invalid int.");
positive = false;
}
boolean first = true;
while(true) {
if(!pumpBuf()) break;
if(isDelimiter(buf[bufi])) {
if(first) throw new RuntimeException("IO.nextInt: Invalid int.");
break;
}
first = false;
if(buf[bufi] >= '0' && buf[bufi] <= '9') {
if(ret < -214748364) throw new RuntimeException("IO.nextInt: Invalid int.");
ret *= 10;
ret -= (int)(buf[bufi] - '0');
if(ret > 0) throw new RuntimeException("IO.nextInt: Invalid int.");
} else {
throw new RuntimeException("IO.nextInt: Invalid int.");
}
++bufi;
}
if(positive) {
if(ret == -2147483648) throw new RuntimeException("IO.nextInt: Invalid int.");
ret = -ret;
}
return ret;
} catch(IOException e) {
throw new RuntimeException("IO.nextInt: Caught IOException.");
}
}
public long nextLong() {
try {
long ret = 0;
eatDelimiters();
boolean positive = true;
if(buf[bufi] == '-') {
++bufi;
if(!pumpBuf()) throw new RuntimeException("IO.nextLong: Invalid long.");
positive = false;
}
boolean first = true;
while(true) {
if(!pumpBuf()) break;
if(isDelimiter(buf[bufi])) {
if(first) throw new RuntimeException("IO.nextLong: Invalid long.");
break;
}
first = false;
if(buf[bufi] >= '0' && buf[bufi] <= '9') {
if(ret < -922337203685477580L) throw new RuntimeException("IO.nextLong: Invalid long.");
ret *= 10;
ret -= (long)(buf[bufi] - '0');
if(ret > 0) throw new RuntimeException("IO.nextLong: Invalid long.");
} else {
throw new RuntimeException("IO.nextLong: Invalid long.");
}
++bufi;
}
if(positive) {
if(ret == -9223372036854775808L) throw new RuntimeException("IO.nextLong: Invalid long.");
ret = -ret;
}
return ret;
} catch(IOException e) {
throw new RuntimeException("IO.nextLong: Caught IOException.");
}
}
public double nextDouble() {
return Double.parseDouble(next());
}
}
