problem 1134 type of fuel.c

#include <stdio.h>
int main()
{
    int a, x=0, y=0, z=0;
    while(1)
    {
        scanf("%d", &a);
        if(a==4)
            break;
        else
        {
            if(a==1) x++;
            else if(a==2) y++;
            else if(a==3) z++;
            else continue;
        }
    }
    printf("MUITO OBRIGADO\n");
    printf("Alcool: %d\n",x);
    printf("Gasolina: %d\n",y);
    printf("Diesel: %d\n",z);
    return 0;
}