```
#include<stdio.h>
unsigned long int call( unsigned long int);
int main()
{
int t=0,i;
unsigned long int n;
// scanf("%d",&t);
while(t==0){
scanf("%lu",&n);
printf("%lu\n",call(n));
//t--;
}
}
long unsigned int call(long unsigned int n)
{
long unsigned int a,b,c,x,y,z,m,l;
a=n/2;
b=n/3;
c=n/4;
m=a+b+c;
if(m>n)
{
x=call(a);
y=call(b);
z=call(c);
l=x+y+z;
if(l>m)
return (l);
else
return(m);
}
else
{
return n;
}
}
```

this is code i have written. tell me any possible way to reduce the execution time of this code. i have used shorthand operators and everything i can do. please help. thanks