int main(int argc, char *argv[]){
cout<<"Parent pid: "<<getpid<<endl;
int a = fork();
int b = fork();
if(a==0)
{
cout<<"pid: "<<getpid<<endl;
system(">rno1.txt");
ofstream myfile("rno1.txt");
myfile.open("rno1.txt");
for(int i=0;i<20;i++){
int z = rand()%1000000000;
myfile<<z;
myfile.close();}
}
if(b==0){
cout<<"pid: "<<getpid<<endl;
system(">rno2.txt");
ofstream myfil("rno2.txt");
myfil.open("rno2.txt");
for(int i=0;i<20;i++){
int y = rand()%1000000000;
myfil<<y;
myfil.close();
}
}

else if(a>0){
wait(NULL);
c = fork();
if(c==0){
cout<<"pid: "<<getpid<<endl;
int counter = 0;
ifstream f1("rno1.txt");
ifstream f2("rno2.txt");
int num[20];
int num2[20];
for(int i=0;i<20;i++){
f1>>num[i];
f2>>num2[i];

}
for(int i=0;i<20;i++){
for(int j=0;j<20;j++){
int count = 0;
if(num[i]==num2[j])
cout<<num[i];
count ++;
}
}
if(count==0)
cout<<"no common number";
system("rm rn01.txt");
system("rm rn02.txt");}



}


}