During Problem Set i came across the error Expected Expression on the statement "string s = GetString();" Suggestions would be appreciated. The code is provided below. #include <cs50.h> #include <stdio.h> #include <string.h> #include <ctype.h> int main(void) { int s = 0; // Height int t = 0; // Line int u = 0; // Column do { // Gathers string. printf("Please provide the height of the pyramid: "); string s = GetString(); } while (s < 1 || s > 23); // Selects a line. for (int t = 1; t <= s; t++) { // Selects a column. for (int u = 1; u <= s; u++) { // Prints character. if (u >= s + 1 - t) { printf("#"); } else { printf(" "); } } } // Prints next line. printf("\n"); }