C :

#include <stdio.h>
int main(){
	int i,n1,n2,tmp,n;
	unsigned int v;
//	freopen("1.txt","r",stdin);
	while (scanf("%u %d %d",&v,&n1,&n2)==3)
	{
		tmp=0;
		n=1;
		for (i=n1;i<=n2;i++)
		{
			tmp|=n<<i;
		}
		printf("%u\n",v&tmp);
	}
//	fclose(stdin);
	return 0;
}

C++ :

#include <stdio.h>
int main() {
	unsigned int getbits(unsigned int, int, int);
	unsigned int a;
	int n1, n2;
	scanf("%u %d %d", &a, &n1, &n2);
	printf("%u\n", getbits(a, n1, n2));
	return 0;
}
unsigned int getbits(unsigned int a, int n1, int n2) {
	return (a & (((1 << n2) - 1) ^ ((1 << n1) - 1)));
}