Go: package main

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

func main() {
	io := NewIo()
	defer io.Flush()
	for {
		n := io.NextInt()
		if n == 0 {
			break
		}
		s := make([]string, n)
		for i := 0; i < n; i++ {
			s[i] = io.NextLine()
		}
		w := [5]int{5, 7, 5, 7, 7}
		ans := 0
	OUTER:
		for i := 0; i < n; i++ {
			cnt, wc := 0, 0
			for j := i; j < n; j++ {
				wc += len(s[j])
				if wc == w[cnt] {
					cnt++
					wc = 0
					if cnt == 5 {
						ans = i + 1
						break OUTER
					}
				} else if wc > w[cnt] {
					break
				}
			}
		}
		io.Println(ans)
	}
}

// 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 := make([]interface{}, 0, len(a))
	for _, x := range a {
		b = append(b, x)
	}
	io.Println(b...)
}

func (io *Io) PrintStringSlice(a []string) {
	b := make([]interface{}, 0, len(a))
	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>
#include <string>
#include <vector>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <stack>
#include <queue>
#include <set>
#include <map>
#include <utility>
#include <ctime>
#define INF 999999999
#define mod 1000000007

#define rep(i,n) for(int i=0;i<int(n);i++)
#define rrep(i,n) for(int i=(n);i>=0;i--)
#define REP(i,a,b) for(int i=(a);i<int(b);i++)
#define all(x) (x).begin(),x.end()
#define pb push_back
#define MOD(x) (x%(mod))
using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef vector<int> vi;
typedef pair<int,int> pi;

int dx[4]={1,0,-1,0};
int dy[4]={0,1,0,-1};
bool debug=false;
/*---------------------------------------------------*/

int haiku[45];
int num[6]={5,7,5,7,7,0};

void solve(int n){
  int s=0,e=0,cnt=0,sum=haiku[0];
  int dast=0;
  int ans=INF;
  rep(i,n-5){
    dast=0;
    s=e=i;
    while(s!=n-1&&e!=n-1){
      if(debug)cout<<"s: "<<s<<"  e:"<<e<<"  cheack( "<<cnt<<" ): "<<num[cnt]<<"  dast: "<<dast<<endl;
      if(cnt==5)break;
      if(sum==num[cnt]){
	cnt++;s=e=e+1;sum=haiku[s];
      }else if(sum<num[cnt]){
	e++;sum+=haiku[e];
      }else if(sum>num[cnt]){
	sum-=haiku[s];s++;
	dast++;
      }
    }
    dast+=(n-e);
    ans=min(ans,dast);
  }
  cout<<ans<<endl;
}


int main(){
  int n;
  string s;
  while(cin>>n){
    if(n==0)break;
    rep(i,n){cin>>s;haiku[i]=s.size();}
    solve(n);
  }
}

C++: #include"bits/stdc++.h"
#define rep(i,n) for(int i=0;i<n;i++)
typedef long long ll;
using namespace std;

char c[40][15];

int main(){
	int n;
	while (scanf("%d", &n), n){
		int want[] = { 5, 7, 5, 7, 7 };
		int cnt = 0;
		int j = 0;
		for (int i = 0; i < n; i++){
			scanf("%s", c[i]);
		}
		int t;
		for (t = 0; t < n; t++){
			for (int i = t; i < n; i++){
				cnt += strlen(c[i]);
				if (cnt == want[j]){
					cnt = 0;
					if (++j == 5)break;
				}
				if (cnt > want[j])break;
			}
			if (j == 5)break;
			j = 0;
			cnt = 0;
		}
		printf("%d\n", t+1);
	}
	return 0;
}

C++: #include <bits/stdc++.h> // {{{
// clang-format off
#define ARG4(_1, _2, _3, _4, ...) _4
#define rep(...) ARG4(__VA_ARGS__, FOR, REP)(__VA_ARGS__)
#define REP(i, a) FOR(i, 0, a)
#define FOR(i, a, b) for (int i = (a); i < (int)(b); ++i)
#define rrep(...) ARG4(__VA_ARGS__, RFOR, RREP)(__VA_ARGS__)
#define RREP(i, a) RFOR(i, 0, a)
#define RFOR(i, a, b) for (int i = (b)-1; i >= (int)(a); --i)
#define ALL(c) (c).begin(), (c).end()
#define TEN(n) ((ll)(1e##n))
#define pb emplace_back
#define mp make_pair
#define fi first
#define se second
#define USE1(T) template <typename T> inline
#define USE2(T, U) template <typename T, typename U> inline
#define mygc(c) (c) = getchar_unlocked()
#define mypc(c) putchar_unlocked(c)
 
template<typename T> using vec = std::vector<T>;
template<typename T> using withi = std::pair<T, int>;
using ll = long long;
USE2(T,U)bool chmax(T&x,U a){return x<a&&(x=a,1);}
USE2(T,U)bool chmin(T&x,U a){return a<x&&(x=a,1);}
USE1(T=int)T in(){T x;std::cin>>x;return x;}
USE1(T=int)vec<T>in(int n){vec<T>v;v.reserve(n);rep(i,n)v.pb(in<T>());return v;}
USE2(T,U=withi<T>)vec<U>zipi(const vec<T>&x,int s=0){int N=x.size();vec<U>v;v.reserve(N);rep(i,N)v.pb(x[i],s+i);return v;}
USE1(T)vec<T>ndvec(T v,int n){return vec<T>(n,v);}
USE2(T,...Ts)auto ndvec(T v,int n,Ts...ns)->vec<decltype(ndvec(v,ns...))>{return ndvec(ndvec(v,ns...),n);}
USE1(T)void pr(T x){std::cout<<x<<'\n';}
USE2(T,...Ts)void pr(T x,Ts...xs){std::cout<<x<<' ';pr(xs...);}
USE1(T=int)T rd(){T x=0,m=0,k;for(;;){mygc(k);if(k=='-'){m=1;break;}if('0'<=k&&k<='9'){x=k-'0';break;}}for(;;){mygc(k);if(k<'0'||'9'<k)break;x=x*10+k-'0';}return x;}
USE1(T=int)void wr(T x,char c='\n'){int s=0,m=0;char b[32];if(x<0)m=1,x=-x;for(;x;x/=10)b[s++]=x%10;if(!s)b[s++]=0;if(m)mypc('-');for(;s--;)mypc(b[s]+'0');mypc(c);}
// clang-format on
// }}}
struct IoSetup { // {{{
  IoSetup() {
    std::ios::sync_with_stdio(0);
    std::cin.tie(0);
    std::cout.precision(10);
    std::cerr.precision(10);
  }
} iosetup; //}}}
using namespace std;
const int inf = 1001001001;
const ll infl = 1001001001001001001ll;
const int dd[] = {0, 1, 0, -1, 0};

bool is_haiku(const vector<int>& w, int s) {
  int word[] = {5, 7, 5, 7, 7};
  int st = 0;
  rep(i, s, w.size()) {
    word[st] -= w[i];
    if (word[st] < 0) return false;
    if (word[st] == 0) {
      st++;
      if (st == 5) return true;
    }
  }
  return false;
}

signed main() {
  int N;
  while (N = in(), N) {
    vector<int> w;
    rep(i, N) { w.pb(in<string>().size()); }
    rep(i, N) {
      if (is_haiku(w, i)) {
        pr(i + 1);
        break;
      }
    }
  }
  return 0;
}

C++: #include <iostream>
using namespace std;
int main(){
  int a[]={5,7,5,7,7},n,i,j,c,k;
  while(cin>>n,n){
    string s[n];
    for(i=0;i<n;i++)cin>>s[i];
    for(i=0;i<n;i++){
      c=k=0;
      for(j=i;j<n;j++){
        c+=s[j].size();
        if(c==a[k]){
          c=0;
          if(++k==5)goto L;
        }
      }
    }
    L: if(k==5)cout<<i<<endl;
  }
}