#include <stdio.h>
#include <math.h>

int main() {
    long long binary;
    printf("Enter a binary number: ");
    scanf("%lld", &binary);

    int decimal = 0, i = 0, rem;
    while (binary != 0) {
        rem = binary % 10;
        binary /= 10;
        decimal += rem * pow(2, i);
        ++i;
    }

    printf("Decimal equivalent: %d\n", decimal);
    return 0;
}

#if 0

#include <stdio.h>

void decimalToBinary(int n) {
    int binary[32];
    int i = 0;
    while (n > 0) {
        binary[i] = n % 2;
        n = n / 2;
        i++;
    }
    printf("Binary equivalent: ");
    for (int j = i - 1; j >= 0; j--) {
        printf("%d", binary[j]);
    }
    printf("\n");
}

int main() {
    int decimal;
    printf("Enter a decimal number: ");
    scanf("%d", &decimal);
    decimalToBinary(decimal);
    return 0;
}

#endif