#include <bits/stdc++.h>

//    #include <boost/multiprecision/cpp_int.hpp>
 #define int long long
 #define inf  1000000007
 #define pa pair<int,int>
 #define ll long long
 #define pal pair<double,double>
 #define ppap pair<pa,int>
  #define PI 3.14159265358979323846
  #define paa pair<int,char>
  #define  mp make_pair
  #define  pb push_back
  #define EPS (1e-10)
                                          
    int dx[8]={0,1,0,-1,1,1,-1,-1};
    int dy[8]={1,0,-1,0,-1,1,1,-1};
                                            using namespace std;
                                   			class pa3{
                                            	public:
                                            	int x;
                                   				int y,z;
                                            	pa3(int x=0,int y=0,int z=0):x(x),y(y),z(z) {}
                                            	bool operator < (const pa3 &p) const{
                                            		if(x!=p.x) return x<p.x;
                                            		if(y!=p.y) return y<p.y;
                                            		 return z<p.z;
                                            		//return x != p.x ? x<p.x: y<p.y;
                                            	}
                                   				bool operator > (const pa3 &p) const{
                                            		if(x!=p.x) return x>p.x;
                                            		if(y!=p.y) return y>p.y;
                                            		 return z>p.z;
                                            		//return x != p.x ? x<p.x: y<p.y;
                                            	}
                                            	bool operator == (const pa3 &p) const{
                                            		return x==p.x && y==p.y && z==p.z;
                                            	}
                                            		bool operator != (const pa3 &p) const{
                                            			return !( x==p.x && y==p.y && z==p.z);
                                            	}
                                            
                                            };
                                            
                                            class pa4{
                                            	public:
                                            	int x;
                                            	int y,z,w;
                                            	pa4(int x=0,int y=0,int z=0,int w=0):x(x),y(y),z(z),w(w) {}
                                            	bool operator < (const pa4 &p) const{
                                            		if(x!=p.x) return x<p.x;
                                            		if(y!=p.y) return y<p.y;
                                            		if(z!=p.z)return z<p.z;
                                            		return w<p.w;
                                            		//return x != p.x ? x<p.x: y<p.y;
                                            	}
                                            	bool operator > (const pa4 &p) const{
                                            		if(x!=p.x) return x>p.x;
                                            		if(y!=p.y) return y>p.y;
                                            		if(z!=p.z)return z>p.z;
                                            		return w>p.w;
                                            		//return x != p.x ? x<p.x: y<p.y;
                                            	}
                                            	bool operator == (const pa4 &p) const{
                                            		return x==p.x && y==p.y && z==p.z &&w==p.w;
                                            	}
                                            		
                                            
                                            };
                                            class pa2{
                                            	public:
                                            	int x,y;
                                            	pa2(int x=0,int y=0):x(x),y(y) {}
                                            	pa2 operator + (pa2 p) {return pa2(x+p.x,y+p.y);}
                                            	pa2 operator - (pa2 p) {return pa2(x-p.x,y-p.y);}
                                            	bool operator < (const pa2 &p) const{
                                            		return y != p.y ? y<p.y: x<p.x;
                                            	}
                                            	bool operator > (const pa2 &p) const{
                                            		return x != p.x ? x<p.x: y<p.y;
                                            	}
                                            	bool operator == (const pa2 &p) const{
                                            		return abs(x-p.x)==0 && abs(y-p.y)==0;
                                            	}
                                            	bool operator != (const pa2 &p) const{
                                            		return !(abs(x-p.x)==0 && abs(y-p.y)==0);
                                            	}
                                            		
                                            
                                            };
                                            

                      
                                string itos( int i ) {
                                ostringstream s ;
                                s << i ;
                                return s.str() ;
                                }
                                 
                                int gcd(int v,int b){
                                	if(v>b) return gcd(b,v);
                                	if(v==b) return b;
                                	if(b%v==0) return v;
                                	return gcd(v,b%v);
                                }
                 
                            
                                int mod;
int extgcd(int a, int b, int &x, int &y) {
    if (b == 0) {
        x = 1;
        y = 0;
        return a;
    }
    int d = extgcd(b, a%b, y, x);
    y -= a/b * x;
    return d;
}
pa operator+(const pa & l,const pa & r) {   
    return {l.first+r.first,l.second+r.second};                                    
}    
pa operator-(const pa & l,const pa & r) {   
    return {l.first-r.first,l.second-r.second};                                    
}  
                                
                int pr[1200010];
                int inv[1200010];
                
                int beki(int wa,int rr,int warukazu){
                	if(rr==0) return 1%warukazu;
                	if(rr==1) return wa%warukazu;
                	wa%=warukazu;
                	if(rr%2==1) return ((ll)beki(wa,rr-1,warukazu)*(ll)wa)%warukazu;
                	ll zx=beki(wa,rr/2,warukazu);
                	return (zx*zx)%warukazu;
                }

                
    			int comb(int nn,int rr){
    				if(rr<0 || rr>nn || nn<0) return 0;
    				int r=pr[nn]*inv[rr];
    				r%=mod;
    				r*=inv[nn-rr];
    				r%=mod;
    				return r;
    			}
                
                void gya(int ert){
                	pr[0]=1;
                	for(int i=1;i<=ert;i++){
                		pr[i]=(pr[i-1]*i)%mod;
                	}
                		inv[ert]=beki(pr[ert],mod-2,mod);
                	for(int i=ert-1;i>=0;i--){
                		inv[i]=inv[i+1]*(i+1)%mod;
                	}
                }
                
              //   cin.tie(0);
    		//	ios::sync_with_stdio(false);
    			//priority_queue<pa3,vector<pa3>,greater<pa3>> pq;            
                 //sort(ve.begin(),ve.end(),greater<int>());
//    mt19937(clock_per_sec);
  //  mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count()) ;
      
       
       
                               //----------------kokomade tenpure------------


 	vector<pa3> eda;
 	
vector<pa3> Q;
void ch(string s){
	int it=-1;
	for(int i=0;;i++){
		if(!(s[i]>='0' && s[i]<='9')){
			it=i;
			break;
		}
	}
	
	int a=stoi(s.substr(0,it));
	s=s.substr(it);
	
	string d1;
	
	if(s[0]=='*'){
		d1="*";
		s=s.substr(1);
	}
	else {
		d1=s.substr(0,2);
		s=s.substr(2);
	}
	it=-1;
	for(int i=0;;i++){
		if(s[i]=='+' || s[i]=='-'){
			it=i;
			break;
		}
	}
	
	string d2=s.substr(it,1);
	
	int b,c;
	b=stoi(s.substr(0,it));
	c=stoi(s.substr(it+1));
	
	
	//cout<<a<<" "<<d1<<" "<<b<<" "<<d2<<" "<<c<<endl;
	
	
	if(d1=="<=" && d2=="+"){
			eda.pb({b,a,-c});
	}
	
	if(d1=="<=" && d2=="-"){
			eda.pb({b,a,0});
			eda.pb({a,b,c});
	}
	
	if(d1==">=" && d2=="+"){
			eda.pb({a,b,-c});
	}
	
	if(d1==">=" && d2=="-"){
			eda.pb({a,b,0});
			eda.pb({b,a,c});
	}
	
	if(d1=="*" && d2=="+"){
		if(c==0) return;
			Q.pb({a,b,-c});
	}
	
	if(d1=="*" && d2=="-"){
			eda.pb({b,a,c});
			eda.pb({a,b,c});
	}
	
}


int ans=-1;
int n;

int dis[110];
void solve(){
	for(int i=1;i<=n;i++)dis[i]=inf;
	
	dis[1]=0;
	bool bo;
	
//	for(auto v:eda)cout<<v.x<<" "<<v.y<<" "<<v.z<<endl;
//	cout<<endl;
	for(int i=0;i<=n+2;i++){
		
		bo=false;
		
		for(auto v:eda){
			if(dis[v.y]>dis[v.x]+v.z){
				dis[v.y]=dis[v.x]+v.z;
				bo=1;
			}
		}
	}
	
	if(bo==1) return;
	for(int i=1;i<=n;i++){
		ans=max(ans,dis[i]);
//		cout<<dis[i]<<" ";
	}
//	cout<<endl;
	
}

 signed main(){
 	

    	       cin.tie(0);
   			ios::sync_with_stdio(false);

int m;
 	cin>>n>>m;
 	
 	for(int i=0;i<m;i++){
 		string s;
 		cin>>s;
 		
 		ch(s);
 		
 	}
 		for(int i=2;i<=n;i++)eda.pb({i,1,0});
 	
 	int l=Q.size();
 	for(int i=0;i<(1<<l);i++){
 		
 		for(int j=0;j<l;j++){
 			if(i&(1<<j)){
 				eda.pb(Q[j]);
 			}
 			else{
 				eda.pb(Q[j]);
 				swap(eda.back().x,eda.back().y);
 			}
 		}
 		
 		solve();
 		
 		for(int j=0;j<l;j++)eda.pop_back();
 		
 		
 	}
 	
 	if(ans==inf)cout<<"inf"<<endl;
 	else cout<<ans<<endl;
 	return 0;

  }
  

  


Measured memory_bytes: 3244