#include <stdio.h>

int charToInt(char input[])
{
  int i, summa = 0;

  for (i=0; input[i] != '\0'; i++)
    {
      summa = summa * 10 + input[i] - '0';
    }
  return summa;
}

int main()
{
  char testData[]="3257";
  
  printf("%d\n", charToInt(testData));
  return 0;
}