queue to store odd even number

#include <stdio.h>
int r1=-1,f1=-1,r2=-1,f2=-1,m1=5,m2=5;
int arrs1[5],arrs2[5];
void I1(int i);
void I2(int i);
void del();
void d1();
void d2();
int main() {
    int data,c;
    while(1){
        printf("1=ENQUEUE\n");
        printf("2=INSERT\n");
        printf("3=DELETE\n");
        printf("4=DISPLAY\n");
        printf("5=EXIT\n");
        printf("Choose option");
        scanf("%d",&c);
        switch (c) {
            case 1:{
                printf("Enter data:");
                scanf("%d",&data);
                if(data%2==0){
                    I1(data);
                }
                else
                    I2(data);
                continue;
            }
            case 2:{
                printf("Enter data:");
                scanf("%d",&data);
                if(data%2==0){
                    if(r1!=4){
                        I1(data);
                    }
                    else
                        I2(data);
                }
                continue;
            }
            case 3:{
                del();
            }
            case 4: {
                printf("Even number:\n");
                d1();
                printf("\n");
                printf("Odd num\n");
                d2();
                continue;
            }
            case 5:
                return 0;
        }
    }
}
void I1(int i){
    if (r1 == m1 - 1)
        printf("Queue Overflow \n");
    else
    {
        if (f1 == - 1)
            f1 = 0;
        r1 = r1 + 1;
        arrs1[r1] = i;
    }
}

void I2(int i){
    if (r2 == m2 - 1)
        printf("Queue Overflow \n");
    else
    {
        if (f2 == - 1)
            f2 = 0;
        r2 = r2 + 1;
        arrs2[r2] = i;
    }
}
void d1()
{
    int i;
    if (f1 == - 1)
        printf("Queue is empty \n");
    else
    {
        printf("\n");
        for (i = f1; i <= r1; i++)
            printf("%d ", arrs1[i]);
        printf("\n");
    }
}
void d2()
{
    int i;
    if (f2 == - 1)
        printf("Queue is empty \n");
    else
    {
        printf("\n");
        for ( i= f2; i <= r2; i++)
            printf("%d ", arrs2[i]);
        printf("\n");
    }
}
void del(){
    if(r1>r1){
        f1++;
        ++r2;
    }
    else {
        f2++;
        ++r1;
    }

}