WA on#3,#4,#5,#6

#include<bits/stdc++.h>
using namespace std;
int main(){
	int n;
    string s="",s1;
	scanf("%d",&n);
    while(n>0){
        n-=72;
        cin>>s1;
        s+=s1;
    }
	int i=0,j=1;
	while(i<s.size() && j<s.size()){
		if(i==j) i++;
		int k=0;
		while(s[i+k]==s[j+k]) k++;
		if(s[i+k]<s[j+k]) j+=k+1;
		else i+=k+1;
	}
	i=min(i,j);
	printf("%d",i);
	return 0;
}