#include <stdio.h>

int main() {
    char letter[91];
    int i = 0;
    while(i < 91)
    {
        scanf("%c", &letter[i]);
        if((letter[i] >= 'A')&&(letter[i] <= 'Z'))
        {
            printf("%c", letter[i]+32);
            i++;
        }
        else if (letter[i] == '\n')
        {
            printf("%c", letter[i]);
            i++;
        }
        else{break;}
    }
    return 0;
}

这期神了,,