#include <stdlib.h>
#include <string.h>
#include <unistd.h>

int gen(void){

    int slump,tal,tal2,tal3,counter=0,classs=0;
    time_t tid;
    char class[10];

    slump=time(&tid);
    counter=0;
    while(1){
        srandom(slump);
        slump=random();
        tal=1+(int) (60.0*random()/(RAND_MAX+1.0));
        tal2=1+(int) (60.0*random()/(RAND_MAX+1.0));
        tal3=1+(int) (60.0*random()/(RAND_MAX+1.0));

        if(((tal>47)&&(tal<51)))
        {
            if (tal==48)
            {
                if(((tal2>47)&&(tal2<58)))
                {
                    if (((tal3>47)&&(tal3<58)))
                    {
                        if ((tal2==48))
                        {
                            printf("%c",(char)tal3);
                        }
                        else
                        sprintf(class,"%c%c",(char)tal2,(char)tal3);
                        counter=1;
                     }
                }
            }

            if (tal==49)
            {
                if(((tal2>47)&&(tal2<58)))
                {
                    if (((tal3>47)&&(tal3<58)))
                    {
                        sprintf(class,"%c%c%c",(char)tal,(char)tal2,(char)tal3);
                        counter=1;
                     }
                }
            }

            if(tal==50)
            {
                if(((tal2>47)&&(tal2<51)))
                {
                    if((tal3==48))
                    {
                        sprintf(class,"%c%c%c",(char)tal,(char)tal2,(char)tal3);
                        counter=1;
                    }
                }
            }
        }
        if (counter==1)
        {
            classs=atoi(class);
            return(classs);
        }
    }
    return(0);
}