#include <stdio.h>
 #include <string.h>

// To return value for a character. 10 is returned for 'A'
 int val(char c)
 {
 if (c >= '0' && c <= '9')
 return (int)c - '0';
 else
 return (int)c - 'A' + 10;
 }

// Function to convert a number from given base 'q' to decimal
 int q2num(char num_q[], int q)
 {
 int len = strlen(num_q);
 int power = 1; // Initialize power of base
 int num = 0; // Initialize result
 int i;

// Decimal equivalent is str[len-1]*1 +
 // str[len-2]*base + str[len-3]*(base^2) + ...
 for (i = len - 1; i >= 0; i--)
 {
 // A digit in input number must be
 // less than number's base
 if (val(num_q[i]) >= q)
 {
 printf("Invalid Number");
 return -1;
 }

num += val(num_q[i]) * power;
 power = power * q;
 }

return num;
 }
 // Driver program
 int main()
 {
 int base = 16;
 char temp[3]="11A";
 printf("%d",q2num(temp,base));

return 0;
 }