Extract and Modify Field in a 32-bit Register

#include <stdio.h>
#include <stdint.h>

uint32_t update_register(uint32_t reg) {
   uint16_t a;
   a = (reg>>10) & ((1<<5)-1);
   if(a<0x1F){
    a++;
    reg = reg & ~(0x1F<<10); //clear bit 10-14
    reg = reg | (a<<10);     //add modified field at bit 10-14
   }
    return reg;
}

int main() {
    uint32_t reg;
    scanf("%u", &reg);
    uint32_t updated = update_register(reg);
    printf("%u", updated);
    return 0;
}