奇奇怪怪

#include<cstdio>
#include<cstring>

int main(){
	char a[51];
	int n,i;
	scanf("%d%s",&n,a);
	for(i=0;i<strlen(a);i++){
		a[i]+=n;
		while(a[i]>'z')
			a[i]-='z';
	}
	printf("%s",a);
	return 0;
}

样例过了，#3#4$\color{red}\text{WA}$