0分到底哪错了？？

#include<bits/stdc++.h>
using namespace std;
int main(){
	long long n,x;
	char m1[2],m2[2];
	scanf("%lld",&n);
	for(int i=0;i<n;i++){
		scanf("%lld %s = ? %s",&x,m1,m2);
		if(m1[0]=='k'&&m1[1]=='m'){
			if(strlen(m2)==1)printf("%lld km = %lld m\n",x,x*1000);
			else printf("%lld km = %lld mm\n",x,x*1000000);
		}
		else if(m1[0]=='k'&&m1[1]=='g'){
			if(m2[0]=='g')printf("%lld km = %lld m\n",x,x*1000);
			else printf("%lld km = %lld mm",x,x*1000000);
		}
		else if(m1[0]=='m')printf("%lld m = %lld mm\n",x,x*1000);
		else printf("%lld g = %lld mg\n",x,x*1000);
	}
	return 0;
}