Capital small and digits from a string line input

#include<stdio.h>
#include<string.h>
int main()
{
    int  i,capital=0,small=0,digit=0;
    char str[40]="SUit MA QueeN02";
    for(i=0; i<strlen(str); i++)
    {

        if(str[i]>='A' && str[i]<='Z')
        {

            capital++;
        }
        if(str[i]>='a' && str[i]<='z')
        {
            small++;
        }
        if(str[i]>='0' && str[i]<='9')
        {
            digit++;
        }
    }
    printf(" Capitals are in %d",capital);
    printf("\nSmalls are in %d",small);
    printf("\nDigits are in %d",digit);
return 0;
}