/*
#include <stdio.h>
int main()
{
int a,b;
scanf("%d %d",&a, &b);
printf("%d",(a&&!b)||(!a&&b));
return 0;
}
*/
/*
#include <stdio.h>
int main()
{
int a,b;
scanf("%d %d",&a, &b);
printf("%d",(!a&&!b)||(a&&b));
return 0;
}
*/
/*
#include <stdio.h>
int main()
{
int a,b;
scanf("%d %d",&a, &b);
printf("%d",(!a&&!b));
return 0;
}
*/
/*
#include <stdio.h>
int main()
{
long long int a,b;
scanf("%lld %lld",&a, &b);
printf("%lld",a+b);
return 0;
}
*/
/*
#include <stdio.h>
int main()
{
int a,b;
scanf("%d %d",&a, &b);
printf("%d+%d=%d\n",a,b,a+b);
printf("%d-%d=%d\n",a,b,a-b);
printf("%d*%d=%d\n",a,b,a*b);
printf("%d/%d=%d",a,b,a/b);
}
*/
/*
#include <stdio.h>
int main()
{
int a,b;
scanf("%d %d",&a, &b);
printf("%.1lf",a*b/2.0);
return 0;
}
*/
/*
#include <stdio.h>
int main()
{
float a,b,c;
scanf("%f %f %f",&a, &b, &c);
printf("%.2f",(a+b+c)/3);
return 0;
}
*/