Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
)

func main() {
	io := NewIo()
	defer io.Flush()
	for {
		h := io.NextInt()
		if h == 0 {
			break
		}
		p := make([][]int, h)
		for i := 0; i < h; i++ {
			p[i] = make([]int, 5)
			for j := 0; j < 5; j++ {
				p[i][j] = io.NextInt()
			}
		}
		ans := 0
		for {
			sc := puyo(p, h)
			if sc == 0 {
				break
			}
			fall(p, h)
			ans += sc
		}
		io.Println(ans)
	}
}

func puyo(p [][]int, h int) int {
	sc := 0
	for i := 0; i < h; i++ {
		for j := 0; j < 3; j++ {
			var cnt int
			for cnt = 1; j+cnt < 5; cnt++ {
				if p[i][j] != p[i][j+cnt] {
					break
				}
			}
			if cnt > 2 {
				sc += p[i][j]*cnt
				for k := 0; k < cnt; k++ {
					p[i][j+k] = 0
				}
			}
		}
	}
	return sc
}

func fall(p [][]int, h int) {
	for j := 0; j < 5; j++ {
		for k := 1; k < h; k++ {
			for i := h - 1; i >= k; i-- {
				if p[i][j] == 0 {
					p[i][j] = p[i-1][j]
					p[i-1][j] = 0
				}
			}
		}
	}
}

// I/O template
type Io struct {
	reader    *bufio.Reader
	writer    *bufio.Writer
	tokens    []string
	nextToken int
}

func NewIo() *Io {
	return &Io{
		reader: bufio.NewReader(os.Stdin),
		writer: bufio.NewWriter(os.Stdout),
	}
}

func (io *Io) Flush() {
	err := io.writer.Flush()
	if err != nil {
		panic(err)
	}
}

func (io *Io) NextLine() string {
	var buff []byte
	for {
		line, isPrefix, err := io.reader.ReadLine()
		if err != nil {
			panic(err)
		}
		buff = append(buff, line...)
		if !isPrefix {
			break
		}
	}
	return string(buff)
}

func (io *Io) Next() string {
	for io.nextToken >= len(io.tokens) {
		line := io.NextLine()
		io.tokens = strings.Fields(line)
		io.nextToken = 0
	}
	s := io.tokens[io.nextToken]
	io.nextToken++
	return s
}

func (io *Io) NextInt() int {
	i, err := strconv.Atoi(io.Next())
	if err != nil {
		panic(err)
	}
	return i
}

func (io *Io) NextFloat() float64 {
	i, err := strconv.ParseFloat(io.Next(), 64)
	if err != nil {
		panic(err)
	}
	return i
}

func (io *Io) Println(a ...interface{}) {
	fmt.Fprintln(io.writer, a...)
}

func (io *Io) Printf(format string, a ...interface{}) {
	fmt.Fprintf(io.writer, format, a...)
}

func (io *Io) PrintIntSlice(a []int) {
	b := []interface{}{}
	for _, x := range a {
		b = append(b, x)
	}
	io.Println(b...)
}

func (io *Io) PrintStringSlice(a []string) {
	b := []interface{}{}
	for _, x := range a {
		b = append(b, x)
	}
	io.Println(b...)
}

func Log(name string, value interface{}) {
	fmt.Fprintf(os.Stderr, "%s=%+v\n", name, value)
}

func ExampleIo() {
	io := NewIo()
	defer io.Flush()
	a := make([]int, 0, 3)
	a[0], a[1], a[2] = io.NextInt(), io.NextInt(), io.NextInt()
	io.Println(a)
	io.PrintIntSlice(a)
	Log("io", a)
}

C++: #include <iostream>
#include <algorithm>
using namespace std;

int main()
{
  while(1){
    int H;
    cin >> H;
    if(H == 0) break;
    int p[H][5];
    int ans = 0;
    for(int i = 0; i < H; i++)
      for(int j = 0; j < 5; j++)
        cin >> p[i][j];
    bool flag = true;
    while(flag){
      flag = false;
      for(int i = 0; i < H; i++){
        int x = p[i][2];
        if(x == -1) continue;
        int n = count(&p[i][0], &p[i + 1][0], x);
        if(n == 3){
          if(p[i][0] == x && p[i][1] == x){
            flag = true;
            ans += 3 * x;
            for(int j = 0; j < 3; j++)
              p[i][j] = -1;
          }else if(p[i][3] == x && p[i][4] == x){
            flag = true;
            ans += 3 * x;
            for(int j = 2; j < 5; j++)
              p[i][j] = -1;
          }else if(p[i][1] == x && p[i][3] == x){
            flag = true;
            ans += 3 * x;
            for(int j = 1; j < 4; j++)
              p[i][j] = -1;
          }
        }else if(n == 4){
          flag = true;
          ans += 4 * x;
          if(p[i][0] == x){
            for(int j = 0; j < 4; j++)
              p[i][j] = -1;
          }else{
            for(int j = 1; j < 5; j++)
              p[i][j] = -1;
          }
        }else if(n == 5){
          flag = true;
          ans += 5 * x;
          for(int j = 0; j < 5; j++)
            p[i][j] = -1;
        }
      }
/*
      for(int j = 0; j < H; j++){
        for(int k = 0; k < 5; k++){
          cout << p[j][k];
        }
        cout << endl;
      }
*/    
      
      for(int j = H - 1; j > 0; j--){
        for(int k = 0; k < 5; k++){
          if(p[j][k] == -1){
            for(int l = j - 1; l >= 0; l--){
              if(p[l][k] != -1){
                swap(p[j][k], p[l][k]);
                break;
              }
            }
          }
        }
      }

/*
      for(int j = 0; j < H; j++){
        for(int k = 0; k < 5; k++){
          cout << p[j][k];
        }
        cout << endl;
      }
      */
      
    }
    cout << ans << endl;
  }
}

C++: #define _USE_MATH_DEFINES
#include <cmath>
#include <string>
#include <vector>
#include <utility>
#include <iostream>
#include <algorithm>
#include <unordered_map>
#include <numeric>
#include <array>
#include <float.h>
#include <memory>
#include <functional>
#include <iomanip>
#include <queue>
#include <random>
#include <map>
#include <set>

#pragma warning(disable:4996)

using namespace std;

int table[15][5] = { 0 };

int DeletePiece(int H) {
  int score = 0;
  for (int y = 0; y < H; ++y) {
    vector<pair<int, int>> chain;
    chain.push_back({ 0,0 });
    int index = 0;
    for (int x = 1; x < 5; ++x) {
      if (table[y][x - 1] == table[y][x]) {
        ++chain[index].first;
        chain[index].second = table[y][x];
      }
      else{
        chain.push_back({ 0,table[y][x] });
        ++index;
      }
    }
    auto it = max_element(chain.begin(), chain.end(), [](auto& pair_1, auto& pair_2) {return pair_1.first < pair_2.first; });
    if (it->first >= 2 && it->second!=0) {
      for (int x = 0; x < 5; ++x) {
        if (table[y][x] == it->second) {
          table[y][x] = -1;
          score += it->second;
        }
      }
    }
  }
  return score;
}

void ReplacePiece(int H) {
  for (int y = H - 1; y >= 0; --y) {
    for (int x = 0; x < 5; ++x) {
      while (table[y][x] == -1) {
        for (int yy = y; yy > 0; --yy) {
          table[yy][x] = table[yy - 1][x];
        }
        table[0][x] = 0;
      }
    }
  }
}

int main() {
  while (true) {
    int H;
    int score = 0, tmp_score = 0;
    cin >> H;
    if (H == 0) {
      break;
    }
    for (int y = 0; y < H; ++y) {
      for (int x = 0; x < 5; ++x) {
        cin >> table[y][x];
      }
    }
    do {
      tmp_score = DeletePiece(H);
      score += tmp_score;
      ReplacePiece(H);
    } while (tmp_score != 0);
    cout << score << endl;
  }
  return 0;
}