/*#include <stdio.h>
#include <stdlib.h>
int main()
{
printf("Hello world!\n");
return 0;
}
*/
/*#include <stdio.h>
int main ()
{
int n,k,d,sum=1;
scanf("%d %d",&n,&k);
for(d=1; d<=k; d++){
sum=sum*n;
}
printf("%d",sum);
return 0;
}
*/
/*#include <stdio.h>
int main ()
{
int n,d,sum=1;
scanf("%d",&n);
for(d=1; d<=n; d++){
sum=sum*d;
}
printf("%d",sum);
return 0;
}
*/
/*#include <stdio.h>
int main ()
{
int a,b,d,sum=0;
scanf("%d %d",&a,&b);
for(d=a; d<=b; d++){
if(d%2==0){
sum=sum-d;
}
else{
sum=sum+d;
}
}
printf("%d",sum);
return 0;
}*/
/*#include <stdio.h>
int main ()
{
int n,a,sum=0;
scanf("%d",&n);
for(a=1; sum<n; a++){
sum=sum+a;
}
printf("%d",a-1);
return 0;
}
*/