#include <stdio.h>

int main(void) {
    int i, j, sum, m, n;
    char ch;

    printf("Please enter a character:");
    scanf("%c", &ch);
    sum = ch - 'A' + 1; //总行数

    for (i = 1; i <= sum; i++) {
        for (j = 0; j < sum - i; j++)
            printf(" ");
        for (m = 1; m <= i; m++)
            printf("%c", 'A' - 1 + m);
        for (n = 1; n < i; n++)
            printf("%c", 'A' - 2 + m - n);

        printf("\n");

    }

    return 0;
}