#include<iostream>
using namespace std;

int main(){
  int n;
  cin >> n;
  
  long long int result;
  int i;
  
  result = 1;
  if(n%2 == 1){
    //ODD
    result = 7;
  }
  
  for(i=0;i< n/2-1 ;i++){
    result *= 10;
    result++;
  }

  cout << result << endl;
  
  return 0;
}