error id return 1 exist status

[JuanKa]

me peuden ayudar con este codigo, me sale error id return 1 exist status
como lo corrigo

#include <iostream>
#include <math.h>   
using namespace std;
int main(){
int x;
int y;
int a;
int b;
int c;
int d;
int w;
int E=0;
int e=0;
cout<<" imprime 0 como: E OR e equivalente a zcero "<<endl;
cin>>w;
if(w==0)
cout << "Dato cifrado es :" << endl;
cin >>x;

if(( x<1000 )||( x>9999 ))


a = ( x / 1000 ) % 10;
b = ( x / 100 ) % 10;
c = ( x / 10 ) % 10;
d = x % 10;



a = (a + 7)%10-5;
b = (b + 7)%10;
c = (c + 7)%10;
d = (d + 7)%10;

cout << "Encriptacion completa: " << c<< d << a << b << endl;
cout << " el dato descifrado es  :" << endl;
cin >> y;
a = ( y / 10 ) % 10;
b = y % 10;
c = ( y / 1000 ) % 10;
d = ( y / 100 ) % 10;
   
if( a < 7 ){
a=a+10;}
else if( b < 7 )
{b =b+ 10;}
else if( c < 7 )
{c =c+ 10;}
else if( d < 7 )
{d =d+10;}
a =a- 7;
b =b-7;
c = c-7;
d =d- 7+10;


cout << "Decryption is completed: " << a << b << c << d << endl;

  return 0;
}